BR112019019879B1 - NETWORK NODE, WIRELESS DEVICE AND RELATED METHODS - Google Patents

Abstract

According to certain embodiments, a method is described for use in a network node. The method comprises determining at least one parameter N per carrier frequency. The parameter N indicates a maximum number of beams by a wireless device for signal measurements in a cell. The method comprises communicating the parameter(s) N to the wireless device.

Description

FIELD OF TECHNIQUE

[001] Certain embodiments of the present invention relate generally to wireless networks and more particularly to the configuration of cell quality derivation.

BACKGROUND

[002] The Third Generation Partnership Project (3GPP) is discussing multiple antenna schemes for New Radio (NR). For NR, frequency bands up to 100 GHz are considered. High-frequency radio communication above 6 GHz is known to suffer from path loss and penetration loss. One solution to this issue is to employ large-scale antenna arrays to achieve high beamforming gain, which is a reasonable solution due to the short wavelength of the high-frequency signal. Therefore, multiple-input, multiple-output (MIMO) schemes for NR are also called massive MIMO. For approximately 30/70 GHz, up to 256 transmit (Tx) and receive (Rx) antenna elements are considered. The extension to support 1024 Tx at 70 GHz is stipulated and is under discussion for 30 GHz. For communication below 6 GHz, there is also a trend to increase the number of antenna elements to obtain more beamforming and multiplexing gain.

Beamforming approaches

[003] With massive MIMO, three approaches to beamforming have been discussed: analog, digital, and hybrid (a combination of analog and digital). Analog beamforming would compensate for the high path loss in NR scenarios, while digital beamforming precodes additional performance gains similar to MIMO for sub-6 GHz needed to achieve reasonable coverage. The implementation complexity of analog beamforming is significantly lower than digital precoding since, in many implementations, it relies on simple phase shifters, but its disadvantages are its limited flexibility in multiple directions (i.e., a single beam can be formed at a time and the beams are then switched in the time domain), only wideband transmissions (i.e., transmission over a subband is not possible), unavoidable inaccuracies in the analog domain, etc. Digital beamforming (which requires expensive converters to/from the digital domain to/from the IF domain), currently used in LTE, provides the best performance in terms of data rate and multiplexing capabilities (multiple beams over multiple subbands can be formed simultaneously), but at the same time, it is challenging in terms of power consumption, integration, and cost; furthermore, the gains do not scale linearly with the number of transmit/receive units, while the cost is rising rapidly. Therefore, it is desirable for NR to support hybrid beamforming to benefit from the cost-efficient analog beamforming and the high capacity of digital beamforming. An example diagram for hybrid beamforming is shown in Figure 1. Beamforming can be on transmit beams and/or receive beams on the network side or on the wireless device side. Examples of multibeam base stations can be found in U.S. Patent Publication No. 2004/235527 and Korean Patent Publication No. 2016 0143509.

Beam scanning

[004] The analog beam of a subarray can be oriented in a single direction in each Orthogonal Frequency Division Multiplexing (OFDM) symbol, and therefore, the number of subarrays determines the number of beam directions and the corresponding coverage in each OFDM symbol. However, the number of beams to cover the entire service area is typically greater than the number of subarrays, especially when the individual beamwidth is narrow. Therefore, to cover the entire service area, multiple transmissions with narrow beams oriented differently in the time domain are also likely necessary. The provision of multiple narrow coverage beams for this purpose has been termed “beam scanning.” For analog and hybrid forming, beam scanning appears to be essential to provide basic coverage in NR. For this purpose, multiple OFDM symbols in differently oriented beams can be transmitted through subarrays, can be assigned, and can be transmitted periodically. Examples of beam scanning are illustrated in Figure 2 (Tx beam scanning on two subarrays) and Figure 3 (Tx beam scanning on three subarrays).

Synchronization Signal (SS) Block Configuration

[005] A non-limiting example of a SS block configuration and SS burst configuration that may be considered in other embodiments is described below.

[006] SS Block: An SS block may be used to transmit a New Radio Primary Synchronization Signal (NR-PSS), a New Radio Secondary Synchronization Signal (NR-SSS), and/or a New Radio Broadcast Physical Channel (NR-PBCH). For a given frequency band, an SS block corresponds to a number (N) of OFDM symbols based on the standard subcarrier spacing, and N is a constant. A wireless device must be able to identify at least the OFDM symbol index, the slot index in a radio frame, and the radio frame number of an SS block. A unique set of possible SS block time locations (e.g., relative to the radio frame or relative to the SS burst set) is specified per frequency band. At least for the multi-beam case, at least the SS block time index is specified for the wireless device. A wireless device may be informed of the position(s) of actual transmitted SS blocks in order to help the wireless device perform measurements in CONNECTED/IDLE mode, receive downlink (DL) data/control on unused SS blocks when in CONNECTED mode, and potentially receive DL data/control on unused SS blocks when in IDLE mode.

[007] SS Burst: One or multiple SS block(s) compose an SS Burst. The maximum number of SS blocks, L, within the SS Burst set may be carrier frequency dependent. For example, for frequency band category #A (e.g., 0 ~ 6 GHz), the number (L) is TBD within L ≤ [16]. For frequency band category #B (e.g., 6 ~ 60GHz), the number is TBD within L ≤ [128].

[008] SS Burst Set: One or multiple SS Bursts further compose(s) an SS Burst set (or series) where the number of SS Bursts within an SS Burst set is finite. From the physical layer specification perspective, at least one SS Burst set periodicity is supported. From the wireless device perspective, SS Burst set transmission is periodic. At least for initial cell selection, the wireless device may consider a standard SS Burst set transmission periodicity for a given carrier frequency (e.g., a carrier frequency among 5 ms, 10 ms, 20 ms, 40 ms, 80 ms, or 160 ms). The wireless device may consider a given SS block to be repeated with an SS Burst set periodicity. By standard, the wireless device cannot consider that the base station (e.g. gNB in NR) transmits the same number of physical beam(s), nor the same physical beam(s) through different SS blocks within an SS Burst set.

[009] For each carrier, the SS blocks may be time-aligned or overlap completely or at least in part, or the beginning of the SS blocks may be time-aligned (e.g., when the actual number of transmitted SS blocks is different in different cells).

[010] An exemplary configuration of SS blocks, SSm Bursts and SS Burst series/set is illustrated in Figure 4.

Mobility Procedure

[011] In LTE, handover decisions at a serving eNodeB (eNB) are made based on events configured in the wireless device based on the network quality of different cells. These measurements are performed based on cell-specific reference signals (CRS) so that a cell quality is derived.

[012] In LTE, the wireless device uses CRS and synchronization signals (PSS/SSS) to find a cell and perform radio resource management (RRM) measurements to derive a cell quality. For both intra-frequency and cross-frequency measurements, the wireless device is expected to meet certain RRM requirements depending on channel conditions and noise levels. To achieve this, the wireless device typically collects periodic (e.g., every 40 ms) CRS-based snapshots (after cell detection) in which coherent and incoherent averages are sampled over a limited bandwidth. The wireless device performs filtering at the physical layer before reporting the measurement results to higher layers. Each time a measurement result is received by the higher layers, the wireless device performs Layer 3 (L3) filtering. In LTE, standardized L3 filtering provides some level of harmonization among wireless devices. However, Layer 1 (L1) filtering parameters are not standardized and are left to the wireless device implementation.

[013] Note 1: In LTE, L3 filtering is standardized, therefore the network can provide a level of harmonization among UEs as well as different cell quality measurements from a UE.

[014] The LTE filtering model, as captured in TS 36.300, is reproduced in Figure 5.

SUMMARY

[015] Certain issues may occur in existing systems, as further explained in this section. In 3GPP, RAN1 terminology considered that at least the combination of NR (NR-PSS/NR-SSS) and PBCH synchronization sequences constitutes a so-called SS Block. This may also contain a Tertiary Synchronization Sequence (TSS) to indicate OFDM symbol timing or equivalent information, but this is still for future study (FFS) in RAN1. An RRC_CONNECTED wireless device attempting to access a target cell must consider that the SS Block may be transmitted in the form of repetitive bursts of SS Block transmissions (so-called “SS Burst”), where such a signal burst consists of several SS Block transmissions one after the other in turn. Additionally, a set of SS Bursts can be grouped together (called an "SS Burst Set"), assuming that the SS Bursts within the SS Burst Sets are related to each other. Both SS Bursts and SS Burst Sets have their own periodicity. In single-beam scenarios, the network could configure time repetition within an SS Burst across a broad beam.

[016] Figure 6 illustrates examples of different configurations of an SS Burst Set. The top example illustrates the time repetition within an SS Burst in a wide beam. The middle example illustrates beam scanning of a small number of beams that uses only one SS Burst in the SS Burst Set. The bottom example illustrates beam scanning of a larger number of beams that uses more than one SS Burst in the SS Burst Set to form a full scan.

[017] The network vendor can choose which of these three alternatives to implement. This choice depends on the tradeoff between i) the overhead caused by periodic, always-scanning transmission of narrow beams vs. ii) the delays and signaling required to configure the wireless device to find a narrow beam for the PDSCH/PDCCH. The implementation shown in the top example in Figure 6 prioritizes i), while the implementation shown in the bottom example in Figure 6 prioritizes ii). The middle example in Figure 6 is an intermediate case, where a wide beam scan is used. In this case, the number of beams to cover the cell is reduced, but in some cases, further refinement is required for narrow-gain beamforming of the physical downlink shared channel (PDSCH).

[018] Regardless of which of these is implemented in each cell, the wireless device must be able to perform cell-based measurements when SS Block signals are being beamformed. According to the latest RAN2 agreements from the RAN2#97 meeting in Athens, the cell quality derivation can be derived from multiple beams and the following was stipulated: Agreement: • 1 Cell Quality can be derived from N best beams where the value of N can be set to 1 or more than 1. • FFS: Details of filtering to be applied • FFS: How the quality of the serving cell is determined (e.g. from the serving beam only or from the cell quality) • FFS: Whether the agreement applies to both additional RS and inactive RS. • FFS: The possibility to consider only beams above a threshold ('good' beams)

[019] One problem that arises is that each implementation may have a different number of beams K (i.e., SS Block Set), which may affect how the network should ideally configure the parameter N (i.e., the number of good beams to be used to perform cell quality derivation). Since N refers to cell quality, one solution could be to always configure the wireless device with N per potential neighboring cell candidate in the measurement configuration. However, this would require the network to always be aware of the best beams. This would also disable the possibility of a wireless device encountering new cells not in the cell configuration list, and without N, the wireless device would not be instructed to perform cell quality derivation. Furthermore, it has also been stipulated in RAN2 that the amount of configuration should be minimized. Another possibility would be to allow each cell to broadcast its parameter N. However, the wireless device would be forced to read system information for each cell it detects.

[020] Certain embodiments of the present invention may provide solutions to the problems described above. In general, certain embodiments configure the parameter N used in multi-beam cell scenarios to define the number of beams that the wireless device should consider to derive cell quality. The configuration is at least per carrier frequency to minimize the amount of configuration required and the inter-node coordination required.

[021] According to certain embodiments, a method is described for use at a network node. The method comprises at least one parameter N per carrier frequency. The parameter N indicates a maximum number of beams to be used by a wireless device for signal measurements in a cell. The method comprises communicating the parameter(s) N to the wireless device.

[022] In some embodiments, the method comprises communicating one or more indicators to the wireless device. Examples of indicators include an indicator that indicates that all carrier frequencies use the same parameter N, an indicator that indicates a set of carrier frequencies that use the same parameter N, an indicator that indicates whether all cells in a group of cells belonging to a particular carrier frequency have the same number of beams, and an indicator that indicates whether the number of beams in cells belonging to a first carrier frequency is the same as the number of beams in cells belonging to a second carrier frequency.

[023] In some embodiments, communicating the parameter(s) N to the wireless device comprises communicating a first parameter N1 and information associating the first parameter N1 with a first carrier frequency, and communicating a second parameter N2 and information associating the second parameter N2 with a second carrier frequency that is different from the first carrier frequency. In some embodiments, the information associating the first parameter N1 with the first carrier frequency comprises a frequency channel number of the first carrier frequency. In some embodiments, the information associating the second parameter N2 with the second carrier frequency comprises a frequency channel number of the second carrier frequency.

[024] In some embodiments, the signal measurements comprise one of the following types of signal measurements: cell-specific reference signal measurements, synchronization signal measurements, or radio resource management (RRM) measurements.

[025] In some embodiments, the at least one parameter N per carrier frequency comprises a first parameter N1 for performing a first type of signal measurements at a first carrier frequency and a second parameter N2 for performing a second type of signal measurements at the first carrier frequency. The second type of signal measurements is different from the first type of signal measurements. For example, in some embodiments, the first parameter N1 is used for performing measurements of synchronization signals and the second parameter N2 is used for performing measurements of cell-specific reference signals.

[026] In some embodiments, the at least one parameter N per carrier frequency is communicated in system information common to all wireless devices.

[027] In some embodiments, the at least one parameter N per carrier frequency is communicated in dedicated signaling to the wireless device.

[028] In some embodiments, the method further comprises sending to the wireless device one or more cell-specific offsets. Each cell-specific offset is associated with a specific cell such that the wireless device adjusts the value of the at least one parameter N according to the cell-specific offset when performing signal measurements of the specific cell. The at least one cell-specific offset may be associated with a serving cell from the network node. The at least one cell-specific offset may be associated with a neighboring cell of another network node. The one or more cell-specific offsets may be configured per carrier frequency. In some embodiments, a cell-specific offset of a new cell may be received from the wireless device.

[029] In some embodiments, the method further comprises determining a UE-specific offset. The UE-specific offset is determined based on the beamforming capabilities of the wireless device. The method comprises sending to the wireless device the UE-specific offset such that the wireless device adjusts the value of the at least one parameter N according to the UE-specific offset.

[030] In some embodiments, the method further comprises receiving information about specific cell offsets for the N parameter at different carrier frequencies. The information is received from one or more other network nodes. The method comprises using the received information when determining at least one N parameter per carrier frequency.

[031] In some embodiments, the method further comprises receiving, from one or more other network nodes, information about a number of beams that each respective network node cell uses for a particular carrier frequency. The method comprises using the received information and the information about the number of beams used in the network node cell itself for the particular carrier frequency to determine a common parameter N for all cells on the particular carrier frequency.

[032] In some embodiments, the method further comprises receiving, from one or more other network nodes, information about the N parameter that each respective network node cell uses for a particular carrier frequency. The method comprises using the received information and information about the N parameter used in the network node cell itself for the particular carrier frequency to determine a common N parameter for all cells on the particular carrier frequency. In some embodiments, the common N parameter is determined based on the maximum N parameter used by the network node or any of the other network nodes, the minimum N parameter used by the network node or any of the other network nodes, the average of N parameters used by the network node and the other network nodes, or the Xth percentile of N parameters used by the network node and the other network nodes.

[033] In some embodiments, the network node comprises the serving cell.

[034] In some embodiments, the parameter N facilitates signal measurements performed by the wireless device in each cell belonging to the same carrier frequency.

[035] In some embodiments, the N parameter facilitates signal measurements performed by the wireless device in a multi-beam cell.

[036] In some embodiments, the parameter(s) N is signaled from the network node to the wireless device in a measurement object information element (MeasObject).

[037] According to certain embodiments, a computer program product is described. The computer program product comprises a non-transitory computer-readable storage medium that has computer-readable program code embedded on the medium. The computer-readable code, when executed by processing circuitry from the network node, causes the network node to perform operations. The operations comprise determining at least one parameter N per carrier frequency. The parameter N indicates a maximum number of beams to be used by a wireless device for signal measurements in a cell. The operations comprise communicating the parameter(s) N to the wireless device. In some embodiments, the computer-readable code, when executed by processing circuitry from the network node, further causes the network node to perform any of the methods for use in a network node described above.

[038] According to certain embodiments, a network node is described. The network node comprises a processing circuitry and a wireless interface. The processing circuitry is operable to determine at least one parameter N per carrier frequency. The parameter N indicates a maximum number of beams to be used by a wireless device for signal measurements in a cell. The wireless interface is operable to communicate the parameter(s) N to the wireless device.

[039] In some embodiments, the processing circuitry is further operable to configure one or more indicators, and the wireless interface is further operable to communicate the indicator(s) to the wireless device. Examples of indicators include an indicator that indicates that all carrier frequencies use the same parameter N, an indicator that indicates a set of carrier frequencies that use the same parameter N, an indicator that indicates whether all cells in a group of cells belonging to a particular carrier frequency have the same number of beams, and an indicator that indicates whether the number of beams in cells belonging to a first carrier frequency is the same as the number of beams in cells belonging to a second carrier frequency.

[040] In some embodiments, the processing circuitry is operable to determine a first parameter N1 and information associating the first parameter N1 with a first carrier frequency, and to determine a second parameter N2 and information associating the second parameter N2 with a second carrier frequency that is different from the first carrier frequency. The wireless interface is operable to communicate the first parameter N1 and the second parameter N2 to the wireless device. In some embodiments, the information associating the first parameter N1 with the first carrier frequency comprises a frequency channel number of the first carrier frequency. In some embodiments, the information associating the second parameter N2 with the second carrier frequency comprises a frequency channel number of the second carrier frequency.

[041] In some embodiments, the signal measurements comprise at least one of the following types of signal measurements: cell-specific reference signal measurements, synchronization signal measurements, or radio resource management (RRM) measurements.

[042] In some embodiments, the at least one parameter N per carrier frequency comprises a first parameter N1 for performing a first type of signal measurements at a first carrier frequency and a second parameter N2 for performing a second type of signal measurements at the first carrier frequency. The second type of signal measurements is different from the first type of signal measurements. For example, in some embodiments, the first parameter N1 is used for performing measurements of synchronization signals and the second parameter N2 is used for performing measurements of cell-specific reference signals.

[043] In some embodiments, the wireless interface is operable to communicate the at least one N parameter per carrier frequency in system information common to all wireless devices.

[044] In some embodiments, the wireless interface is operable to communicate the at least one N parameter per carrier frequency in dedicated signaling to the wireless device.

[045] In some embodiments, the processing circuitry is further operable to determine one or more cell-specific offsets. Each cell-specific offset is associated with a specific cell such that the wireless device adjusts the value of the at least one parameter N according to the cell-specific offset when performing signal measurements of the specific cell. The wireless interface is further operable to send the one or more cell-specific offsets to the wireless device. At least one cell-specific offset may be associated with a serving cell from the network node. At least one cell-specific offset may be associated with a neighboring cell of another network node. The one or more cell-specific offsets may be configured per carrier frequency. In some embodiments, a cell-specific offset of a new cell may be received from the wireless device.

[046] In some embodiments, the processing circuitry is further operable to determine a UE-specific offset. The UE-specific offset is determined based on the beamforming capabilities of the wireless device. The wireless interface is further operable to send to the wireless device the UE-specific offset so that the wireless device adjusts the value of the at least one parameter N according to the UE-specific offset.

[047] In some embodiments, the network node further comprises a network interface. The network interface is operable to receive, from one or more other network nodes, information about specific cell offsets for the N parameter at different carrier frequencies. The processing circuitry is further operable to use the received information when determining at least one N parameter per carrier frequency.

[048] In some embodiments, the network interface is operable to receive, from one or more other network nodes, information about a number of beams that each respective network node cell uses for a particular carrier frequency. The processing circuitry is further operable to use the received information and the information about the number of beams used in the network node cell itself for the particular carrier frequency to determine a common N parameter for all cells on the particular carrier frequency.

[049] In some embodiments, the network interface is operable to receive, from one or more other network nodes, information about the N parameter that each respective network node cell uses for a particular carrier frequency. The processing circuitry is further operable to use the received information and the information about the N parameter used in the network node cell itself for the particular carrier frequency to determine a common N parameter for all cells on the particular carrier frequency. In some embodiments, the common N parameter is determined based on the maximum N parameter used by the network node or any of the other network nodes, the minimum N parameter used by the network node or any of the other network nodes, the average of N parameters used by the network node and the other network nodes, or the Xth percentile of N parameters used by the network node and the other network nodes.

[050] In some embodiments, the network node comprises the serving cell.

[051] In some embodiments, the parameter N facilitates signal measurements performed by the wireless device in each cell belonging to the same carrier frequency.

[052] In some embodiments, the N parameter facilitates signal measurements performed by the wireless device in a multi-beam cell.

[053] In some embodiments, the parameter(s) N is signaled from the network node to the wireless device in a measurement object information element (MeasObject).

[054] According to certain embodiments, a method is described for use in a wireless device. The method comprises receiving at least one N parameter per carrier frequency from the network node. The N parameter indicates a maximum number of beams to be used by the wireless device for signal measurements in a cell. The method comprises using the at least one N parameter.

[055] In some embodiments, the method further comprises receiving one or more indicators. Examples of indicators include an indicator that indicates that all carrier frequencies use the same parameter N, an indicator that indicates a set of carrier frequencies that use the same parameter N, an indicator that indicates whether all cells in a group of cells belonging to a particular carrier frequency have the same number of beams, and an indicator that indicates whether the number of beams in cells belonging to a first carrier frequency is the same as the number of beams in cells belonging to a second carrier frequency.

[056] In some embodiments, in response to the indicator indicating that all cells in the group have the same number of beams, the method further comprises detecting the number of beams at the particular carrier frequency for any cell in the group and considering that the other cells in the group have the same number of beams at the particular carrier frequency.

[057] In some embodiments, in response to the indicator indicating that all cells in the group do not have the same number of beams, the method further comprises detecting the number of beams at the particular carrier frequency in a cell by base by reading system information of the respective cell.

[058] In some embodiments, in response to the indicator indicating that the number of beams in cells belonging to the first carrier frequency is the same as the number of beams in cells belonging to the second carrier frequency, the method further comprises detecting the number of beams on the first carrier frequency and considering that the second carrier frequency has the same number of beams.

[059] In some embodiments, in response to the indicator indicating that the number of beams in cells belonging to the first carrier frequency is not the same as the number of beams in cells belonging to the second carrier frequency, the method further comprises detecting the number of beams on the first carrier frequency and detecting the number of beams on the second carrier frequency.

[060] In some embodiments, the method comprises receiving a first parameter N1 and information associating the first parameter N1 with a first carrier frequency, and receiving a second parameter N2 and information associating the second parameter N2 with a second carrier frequency that is different from the first carrier frequency. In some embodiments, the information associating the first parameter N1 with the first carrier frequency comprises a frequency channel number of the first carrier frequency. In some embodiments, the information associating the second parameter N2 with the second carrier frequency comprises a frequency channel number of the second carrier frequency.

[061] In some embodiments, the use of the at least one parameter N comprises, for each of the one or more carrier frequencies at which the signal measurements are to be performed, using a parameter N that corresponds to the carrier frequency to determine the maximum number of beams to be used for the signal measurements in the cell. The method comprises performing the signal measurements up to the maximum number of beams in the cell. In some embodiments, the method further comprises performing the signal measurements up to the maximum number of beams in a second cell.

[062] In some embodiments, the method further comprises deriving a signal quality and/or a signal strength of the cell based on the signal measurements.

[063] In some embodiments, the signal measurements comprise at least one of the following types of signal measurements: cell-specific reference signal measurements, synchronization signal measurements, or radio resource management (RRM) measurements.

[064] In some embodiments, the at least one parameter N per carrier frequency comprises a first parameter N1 for performing a first type of signal measurements at a first carrier frequency and a second parameter N2 for performing a second type of signal measurements at the first carrier frequency. The second type of signal measurements is different from the first type of signal measurements. For example, in some embodiments, the first parameter N1 is used for performing measurements of synchronization signals and the second parameter N2 is used for performing measurements of cell-specific reference signals.

[065] In some embodiments, the method further comprises using the signal measurements for one or more of the following tasks: reporting to the network node, reporting to a neighboring network node, reporting to another wireless device, changing a cell, positioning the wireless device, performing drive test minimization, and/or performing power control.

[066] In some embodiments, the at least one parameter N per carrier frequency is received in system information common to all wireless devices.

[067] In some embodiments, the at least one N parameter per carrier frequency is received in the dedicated signaling for the wireless device.

[068] In some embodiments, the method further comprises configuring the wireless device with one or more cell-specific offsets. Each cell-specific offset is associated with a specific cell such that the wireless device adjusts the value of the at least one parameter N according to the cell-specific offset when performing signal measurements of the specific cell. At least one cell-specific offset may be associated with a serving cell from the network node. At least one cell-specific offset may be associated with a neighboring cell from another network node. The cell-specific offset associated with the neighboring cell may be received from the serving cell. The one or more cell-specific offsets may be configured per carrier frequency.

[069] In some embodiments, the method further comprises detecting the cell-specific displacement of a new cell and reporting the cell-specific displacement of the new cell to the serving cell.

[070] In some embodiments, the method further comprises configuring the wireless device with a UE-specific offset associated with the particular wireless device such that the wireless device adjusts the value of the at least one parameter N according to the UE-specific offset. In some embodiments, the method determines the UE-specific offset based on the beamforming capabilities of the wireless device. In some embodiments, the UE-specific offset is received from the network node.

[071] In some embodiments, the network node comprises the serving cell.

[072] In some embodiments, the parameter N is used by the wireless device for signal measurements in each cell belonging to the same carrier frequency.

[073] In some embodiments, signal measurements are performed by the wireless device in a multi-beam cell.

[074] In some embodiments, the parameter(s) N is received from the network node by the wireless device in a measurement object information element (MeasObject).

[075] According to certain embodiments, a computer program product is described. The computer program product comprises a non-transitory computer-readable storage medium having computer-readable program code embedded on the medium. The computer-readable code, when executed by processing circuitry of a wireless device, causes the network node to perform operations. The operations comprise receiving, from the network node, at least one N parameter per carrier frequency from the network node, and using the at least one N parameter. The N parameter indicates a maximum number of beams to be used by the wireless device for signal measurements in a cell. In some embodiments, the computer-readable code, when executed by processing circuitry of the wireless device, further causes the wireless device to perform any of the methods for use in a wireless device described above.

[076] According to certain embodiments, a wireless device is described. The wireless device comprises an interface and a processing circuitry. The interface is operable to receive, from the network node, at least one N parameter per carrier frequency. The N parameter indicates a maximum number of beams to be used by the wireless device for signal measurements in a cell. The processing circuitry is operable to use the at least one N parameter.

[077] In some embodiments, the processing circuitry is operable to determine the at least one N parameter per carrier frequency based on receiving an N parameter and an indicator that indicates that all carrier frequencies use the same N parameter.

[078] In some embodiments, the processing circuitry is operable to determine the at least one parameter N per carrier frequency based on a first parameter N1 and an indicator that indicates carrier frequencies using the first parameter N1.

[079] In some embodiments, the at least one received parameter N per carrier frequency comprises a first parameter N1 and information associating the first parameter N1 with a first carrier frequency, and a second parameter N2 and information associating the second parameter N2 with a second carrier frequency that is different from the first carrier frequency. In some embodiments, the information associating the first parameter N1 with the first carrier frequency comprises a frequency channel number of the first carrier frequency. In some embodiments, the information associating the second parameter N2 with the second carrier frequency comprises a frequency channel number of the second carrier frequency.

[080] In some embodiments, the processing circuitry is operable to use a parameter N that corresponds to the carrier frequency to determine the maximum number of beams to be used for signal measurements in the cell, and to perform signal measurements on up to the maximum number of beams in the cell.

[081] In some embodiments, the processing circuitry is further operable to perform signal measurements on up to the maximum number of beams in a second cell.

[082] In some embodiments, the processing circuitry is further operable to derive a signal quality and/or a signal strength of the cell based on the signal measurements.

[083] In some embodiments, the signal measurements comprise at least one of the following types of signal measurements: cell-specific reference signal measurements, synchronization signal measurements, or radio resource management (RRM) measurements.

[084] In some embodiments, the at least one parameter N per carrier frequency comprises a first parameter N1 for performing a first type of signal measurements at a first carrier frequency and a second parameter N2 for performing a second type of signal measurements at the first carrier frequency. The second type of signal measurements is different from the first type of signal measurements. For example, in some embodiments, the first parameter N1 is used for performing measurements of synchronization signals and the second parameter N2 is used for performing measurements of cell-specific reference signals.

[085] In some embodiments, the processing circuitry is further operable to use the signal measurements for one or more of the following tasks: reporting to the network node, reporting to a neighboring network node, reporting to another wireless device, changing a cell, positioning the wireless device, performing drive test minimization, and/or performing power control.

[086] In some embodiments, the interface is further operable to receive, from the network node, an indicator indicating whether all cells in a group of cells belonging to a particular carrier frequency have the same number of beams. In some embodiments, in response to the indicator indicating that all cells in the group have the same number of beams, the processing circuitry is further operable to detect the number of beams at the particular carrier frequency for any cell in the group and consider that the other cells in the group have the same number of beams at the particular carrier frequency. In some embodiments, in response to the indicator indicating that all cells in the group do not have the same number of beams, the processing circuitry is further operable to detect the number of beams at the particular carrier frequency in a cell by reading system information of the respective cell.

[087] In some embodiments, the interfaces are further operable to receive, from the network node, an indicator indicating whether the number of beams in cells belonging to a first carrier frequency is the same as the number of beams in cells belonging to a second carrier frequency. In some embodiments, in response to the indicator indicating that the number of beams in cells belonging to the first carrier frequency is the same as the number of beams in cells belonging to the second carrier frequency, the processing circuitry is further operable to detect the number of beams on the first carrier frequency and consider that the second carrier frequency has the same number of beams. In some embodiments, in response to the indicator indicating that the number of beams in cells belonging to the first carrier frequency is not the same as the number of beams in cells belonging to the second carrier frequency, the processing circuitry is further operable to detect the number of beams on the first carrier frequency and detect the number of beams on the second carrier frequency.

[088] In some embodiments, the at least one parameter N per carrier frequency is received in system information common to all wireless devices.

[089] In some embodiments, the at least one N parameter per carrier frequency is received in the dedicated signaling for the wireless device.

[090] In some embodiments, the processing circuitry is further operable to configure the wireless device with one or more cell-specific offsets. Each cell-specific offset is associated with a specific cell such that the wireless device adjusts the value of the at least one parameter N according to the cell-specific offset when performing signal measurements of the specific cell. At least one cell-specific offset may be associated with a serving cell from the network node. At least one cell-specific offset may be associated with a neighboring cell from another network node. The cell-specific offset associated with the neighboring cell may be received from the serving cell. The one or more cell-specific offsets may be configured per carrier frequency.

[091] In some embodiments, the processing circuitry is further operable to detect the cell-specific offset of a new cell and report the cell-specific offset of the new cell to the serving cell.

[092] In some embodiments, the processing circuitry is further operable to configure the wireless device with a specific UE offset. The specific UE offset is associated with the particular wireless device such that the wireless device adjusts the value of the at least one parameter N according to the specific UE offset. In some embodiments, the processing circuitry determines the specific UE offset based on the beamforming capabilities of the wireless device. In some embodiments, the specific UE offset is received from the network node.

[093] In some embodiments, the network node comprises the serving cell.

[094] In some embodiments, the processing circuitry is operable to use the N parameter for signal measurements in each cell belonging to the same carrier frequency.

[095] In some embodiments, the processing circuitry is operable to perform signal measurements in a multi-beam cell.

[096] In some embodiments, the parameter(s) N is received from the network node by the wireless device in a measurement object information element (MeasObject).

[097] Additional examples are summarized below:

[098] In a first set of embodiments, a method, an apparatus, a system, and a computer program product are proposed wherein a wireless device is configured (i.e., signaled) by a network node with at least one parameter N (number of beams to be used by the wireless device for signal measurements (e.g., cell quality derivation) in a multi-beam cell) per carrier frequency associated with cells that the wireless device is to scan and perform cell-based RRM measurements. The method further comprises the possibility for the wireless device to be configured with specific cell offsets associated with serving cells and neighboring cells.

[099] In a second set of embodiments, the method, apparatus, system, or computer program product further comprises different network nodes that are capable of exchanging information about specific cell offsets for N on different carriers.

[0100] In a third set of embodiments, the method, apparatus, system, or computer program product further comprises different network nodes that are capable of exchanging information about the number of beams used in their respective cells. For example, a first network node (Node1) receives parameters M2 and M3 from the second network node (Node2) and from the third network node (Node3), respectively. M2 and M3 indicate the number of beams used in cell 2 and in cell 3, respectively. Node1 uses its own parameter (M1, i.e., number of beams in cell 1) as well as M2 and M3 to derive a common parameter N for all cells in carrier F1. As an example, M1, M2, and M3 are associated with the same carrier frequency. Then, Node1 transmits N associated with carrier F1 to at least one wireless device in cell 1.

[0101] In a fourth set of embodiments, the method, apparatus, system, or computer program product further comprises different network nodes that are capable of exchanging information about the parameter N (number of beams to be used by the wireless device for signal measurements in a multi-beam cell) used for different carriers by each network node. For example, a first network node (Node1) receives parameters N2 and N3 from the second network node (Node2), and the third network node (Node3) uses them for one or more operational tasks, e.g., determining its own parameter (e.g., N1). As an example, N1, N2, and N3 associated with the same carrier frequency are signaled by Node1, Node2, and Node3 respectively in their respective cells.

[0102] Certain embodiments may provide one or more advantages of the technique. As an example, an advantage of the technique of certain embodiments is that the wireless device only requires the minimum configuration to be able to derive cell quality in scenarios where cells are transmitting reference signals for verification in multiple beams. In certain embodiments, neighboring cell knowledge is available so that the network has the ability to optimize the parameter in a cell-specific displacement manner. Certain embodiments may have all, some, or none of these advantages. Other advantages may be apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE FIGURES

[0103] Figure 1 illustrates an example of hybrid beamforming in accordance with certain embodiments.

[0104] Figure 2 illustrates an example of transmit beam scanning across two subarrays in accordance with certain embodiments.

[0105] Figure 3 illustrates an example of transmit beam scanning across three subarrays in accordance with certain embodiments.

[0106] Figure 4 illustrates an example configuration of synchronization signal (SS) blocks, SS Bursts, and SS Burst sets/series according to certain embodiments.

[0107] Figure 5 illustrates an example of a user equipment filtering model in LTE in accordance with certain embodiments.

[0108] Figure 6 illustrates an example of different configurations of an SS Burst Set in accordance with certain embodiments.

[0109] Figure 7 illustrates an example of a wireless network in accordance with certain embodiments.

[0110] Figure 8 illustrates an example of a wireless device in accordance with certain embodiments.

[0111] Figure 9 illustrates an example of components for a wireless device according to certain embodiments.

[0112] Figure 10 illustrates an example from the network node according to certain embodiments.

[0113] Figure 11 illustrates an example of components for a network node in accordance with certain embodiments.

[0114] Figure 12 illustrates an example of a method for use in a network node in accordance with certain embodiments.

[0115] Figure 13 illustrates an example of a method for use in a wireless device in accordance with certain embodiments.

[0116] Figures 14A-C illustrate example signal flows in which a wireless device receives at least one N parameter per carrier frequency from the network node in accordance with certain embodiments.

[0117] Figures 15-16 illustrate example signal flows in which a network node determines a common parameter N for all cells on a particular carrier frequency in accordance with certain embodiments.

[0118] Figures 17-18 illustrate examples of signal flows in which a network node indicates to a wireless device whether all cells in a cell group belonging to a particular carrier frequency have the same number of beams in accordance with certain embodiments.

[0119] Figures 19-20 illustrate example signal flows in which a network node indicates to a wireless device whether the number of beams in cells belonging to a first carrier frequency is the same as the number of beams in cells belonging to a second carrier frequency in accordance with certain embodiments.

[0120] Figure 21 illustrates an example of a signal flow in which a wireless device is configured with a specific UE offset in accordance with certain embodiments.

[0121] Figures 22 to 24 illustrate examples of signal flows with respect to specific cell offsets in accordance with certain embodiments.

DETAILED DESCRIPTION

[0122] In some embodiments, a non-limiting term “user equipment” (“UE”) is used. The UE herein may be any type of wireless device capable of communicating with a network node or another UE by radio signals. The UE may also be a radio communication device, target device, device-to-device (D2D) UE, machine-type UE, or UE capable of machine-to-machine (M2M) communication, a sensor-equipped UE, iPad, tablet-type computer, mobile terminal, smartphone, integrated laptop-type computer-equipped (LEE), laptop-type computer-mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), etc.

[0123] Furthermore, in some embodiments, the generic terminology “network node” is used. It can be any type of network node that can comprise a radio network node, such as a base station, radio base station, base transceiver station, base station controller, network controller, gNB, NR BS, evolved Node B (eNB), Node B, Multi-Cell Coordination/Multicast Entity (MCE), relay node, access point, radio access point, Remote Radio Unit (RRU), Remote Radio Header (RRH), a multi-standard BS (also known as an MSR BS), a core network node (e.g., mobility management entity (MME), self-organizing network node (SON), a coordination node, positioning node, drive test minimization (MDT) node, etc.), or even an external node (e.g., third-party node, a node external to the current network), etc. The network node may also comprise test equipment.

[0124] The term “network node” used in this document may be used to denote a UE or a radio network node.

[0125] The embodiments are applicable to single carrier operation as well as multi-carrier or carrier aggregation (CA) operation of the UE in which the UE is capable of receiving and/or transmitting data for more than one serving cell. The term carrier aggregation (CA) is also called (e.g., interchangeably called) “multi-carrier system”, “multi-cell operation”, “multi-carrier operation”, “multi-carrier” transmission and/or reception. In CA, one of the component carriers (CCs) is the primary component carrier (PCC) or simply primary carrier or even anchor carrier. The remaining parts are called secondary component carrier (SCC) or simply secondary carriers or even supplementary carriers. The serving cell is interchangeably called primary cell (PCell) or primary serving cell (PSC). Similarly, the secondary serving cell is interchangeably called a secondary serving cell (SCell) or secondary serving cell (SSC).

[0126] The term “signaling” as used herein may comprise any of: higher layer signaling (e.g., via radio resource control (RRC) or the like), lower layer signaling (e.g., via a physical control channel or a broadcast channel), or a combination thereof. Signaling may be implicit or explicit. Signaling may additionally be single broadcast, multicast, or broadcast. Signaling may also be direct to a node or via a third node.

[0127] The term “radio measurement” as used herein may refer to any measurement performed on radio signals. Radio measurements may be absolute or relative. The radio measurement may be referred to as signal level which may be signal quality and/or signal strength. Radio measurements may be, for example, intra-frequency, inter-frequency, CA, etc. Radio measurements may be unidirectional (e.g., downlink (DL) or uplink (UL)) or bidirectional (e.g., round-trip time (RTT), Rx-Tx, etc.). Some examples of radio measurements: timing measurements (e.g., time of arrival (TOA), timing advance, RTT, reference signal time difference (RSTD), Rx-Tx, propagation delay, etc.), angular measurements (e.g., angle of arrival), power-based measurements (e.g., received signal power, reference signal received power (RSRP), received signal quality, reference signal received quality (RSRQ), signal-to-interference plus noise ratio (SINR), signal-to-noise ratio (SNR), interference power, total interference plus noise, received signal strength indicator (RSSI), noise power, etc.), cell detection or cell identification, radio link monitoring (RLM), system information (SI) readout, etc.

[0128] The term “measurement performance” used in this document may refer to any criteria or metric that characterizes the performance of the measurement performed by a network node. The term measurement performance is also called measurement requirement, measurement performance requirements, etc. The network node must meet one or more measurement performance criteria in relation to the measurement performed. Examples of measurement performance criteria are measurement time, number of cells to be measured with the measurement time, measurement reporting delay, measurement accuracy, measurement accuracy relative to a reference value (e.g., ideal measurement result), etc. Examples of measurement time are measurement period, cell identification period, evaluation period, etc.

[0129] In certain embodiments, the network node signals information about a common parameter (N) per carrier frequency that informs the UE about a maximum number of beams whose signals the UE can perform measurements on in any cell on the indicated carrier.

[0130] The carrier frequency information associated with the parameter N is also indicated (i.e., flagged) to the UE. The carrier frequency information may be expressed in terms of a frequency channel number. Examples of a frequency channel number include absolute radio frequency channel number (ARFCN), NARFCN, etc.

[0131] The network node may also signal to the UE a plurality of parameters (e.g., N11, N12, N13, ..., N1m) for a plurality of carrier frequencies (F1, F2, F2, ..., F1m). For example, parameters N11, N12, N13, ..., N1m are associated with carrier frequencies F1, F2, F2, ..., F1m respectively.

[0132] The UE, after receiving one or more beams with respect to the per-carrier parameter (e.g., N11), uses the beam with respect to the parameter(s) to perform one or more radio measurements on one or more beams of one or more cells operating on the carrier (e.g., F1) associated with the signaled parameter.

[0133] For example, consider that the network node signals N=8 beams for the carrier, F1, to the UE. Then, in this case, the UE considers that in each cell belonging to the carrier, F1, the UE can perform measurements up to N=8 beams (e.g., to derive overall cell measurement, e.g., cell quality, signal quality, signal strength, etc.).

[0134] In another aspect of this embodiment, the network node signals an indicator of whether all cells belonging to a particular carrier have the same number of beams or not. In the case where the number of beams is the same in all cells, then the UE may determine the number of beams in any cell of that carrier (e.g., by reading its system information, by blind beam detection, etc.) and consider the same number of beams in the remaining cells. Otherwise, the UE may have to acquire information about the beams in each cell, e.g., by reading the system information (SI) of each cell.

[0135] In yet another aspect of this embodiment, the network node signals an indicator of whether the number of beams in a group of cells (e.g., neighboring cells, all cells of a carrier) on a particular carrier is the same as the number of beams in a reference cell or not. An example of the reference cell is the serving cell. In the case where the number of beams in the group of a cell on the same carrier is the same as the number of beams in the reference cell, then the UE determines the number of beams in the reference cell (e.g., by reading its system information, by blind beam detection, etc.) and considers the same number of beams in the remaining cells. Otherwise, the UE may have to acquire information about the beams in each cell, e.g., by reading each cell's SI.

[0136] In yet another aspect of this embodiment, the network node signals an indicator of whether the number of beams in cells belonging to a particular carrier (e.g., F2) is the same as the number of beams in cells belonging to a certain reference carrier F1 or not. Examples of F1 = PCell carrier and F2 = SCell carrier. In another example, F1 = PCell carrier and F2 may be between carrier frequencies.

[0137] The network node may signal the information (as described above) in a system information message (e.g., common to all UEs) and/or in a UE-specific message (e.g., over a dedicated channel). The information may be transmitted using lower layers (e.g., L1 channel, medium access control (MAC) command) or higher layers (e.g., RRC message, etc.).

[0138] In all of the above variants of the first embodiment, the UE uses the determined value of N per carrier frequency to perform one or more measurements on one or more beams of one or more cells of the carrier associated with the parameter N. The performed measurements are used by the UE for one or more operational tasks. Examples of tasks are reporting the measurement results to the network node (e.g., serving cell), to another UE (e.g., capable of D2D operation, vehicle-to-vehicle (V2V) operation, vehicle-to-anything (V2X) operation, etc.), using the results for cell change (e.g., handover (HO), cell selection, cell reselection, RRC reestablishment, RRC connection release with redirection, etc.), positioning the UE, minimization of drive test (MDT), to perform power control, etc. This is further described below.

[0139] The method comprises a UE that is configured by the network with a carrier frequency-defined parameter N where N is the number of beams to be used by the UE to derive the cell quality in scenarios where each cell transmits its synchronization signals and/or reference signals in multiple beams, such as in the case of SS Block Sets that transmit NR in multiple beams where each beam is transmitting a so-called SS Block.

[0140] For each configured carrier frequency, the UE shall search for cells, and for detected cells, the UE shall use the configured N parameter per carrier to derive the cell quality. Therefore, if the UE finds 7 cells for a given carrier 1 configured with N=5, the UE shall consider 5 beams for all cells contained in that carrier to derive the cell quality values.

[0141] In yet another aspect of this invention, the network node before signaling the parameter N per carrier (or plurality of parameters, N11, N12, ..., N1n for corresponding carriers, F1, F2, ..., Fn respectively), the network node derives the common parameter N based on one or more criteria. This is described below with examples.

[0142] In one example, the network node obtains information about the number of beams used in one or more neighboring cells. The network node may obtain said information based on predefined information (e.g., stored in the network node), information received from another network node (e.g., from the neighboring network node), from a UE, based on antenna configurations used in other cells, etc. Then, the UE may derive a common parameter N based on the obtained information. This is explained with an example below.

[0143] Consider that the network node obtains information about the number of beams M1, M2, M3, ..., Mk used in the ‘k’ cells operating on the same carrier (F1), i.e., cell1, cell2, cell3, ..., cellk respectively. As an example, the common parameter K is derived by using the following function:

[0144] N = F(M1, M2, M3, ..., Mk)

[0145] Examples of the F() function are maximum, minimum, average, X-th percentile, etc.

[0146] Typically, this will require network nodes (e.g., gNBs) to exchange their cell beam information to derive a common value of N for each carrier. The information may also be exchanged between eNB and gNB or between any type of network nodes.

[0147] The method further comprises the possibility for the UE to be provided with cell-specific offset values Ncs(i) per ith cell. In this particular case, once the UE has detected a cell on a carrier configured with Nf(j), the UE should consider N = Nf(j)+ Ncs(i). It is noted that the UE may also be configured with a UE-specific offset such that N = Nf(j)+ Ncs(i)+ Nue, where the network may do so based on the UE beamforming capabilities.

[0148] The method also comprises a network node requesting another specific cell-to-N network node offset for cells on a given carrier. This could be exchanged as part of an interface establishment procedure between nodes where, when the nodes report carrier-defined cells, they may also include this N-cell offset parameter. It could then be used when one of these nodes is configuring a UE to perform cell quality-based measurements.

[0149] The UE method further comprises the UE detecting a cell whose offset was not provided, the UE reading from the broadcasted system information of the detected neighboring cell its cell-specific parameter N and reporting it back to its serving node. It could be a standard and/or triggered procedure where the setup occurs after the UE sends a measurement report with a newly discovered cell based on the N value per carrier and the network detecting this new cell is not in its list of neighboring cells and/or it does not have the cell-specific offset for this cell. It is noted that the network may choose to trigger this procedure only when necessary, such as when failure reports (e.g., radio link reports (RLF), HO failures, etc.) associated with a particular cell are being reported by UEs and/or when cell-based statistics are indicating so.

[0150] Figure 7 is a block diagram illustrating an exemplary wireless network according to certain embodiments. The wireless network includes wireless devices 10A-10N (which may be referred to interchangeably by the non-limiting term user equipment, UE) and a plurality of network nodes, such as radio network nodes 20A-20B (e.g., eNBs, gNBs, base stations, etc.) and one or more core network nodes 30, which may communicate over an interconnection network 25. The wireless devices 10 within the coverage area 15 may each be capable of communicating directly with the radio network nodes 20 over a wireless interface. In certain embodiments, the wireless devices may be capable of communicating with each other via device-to-device (D2D) communication.

[0151] As an example, wireless device 10A may communicate with radio network node 20A over a wireless interface. That is, wireless device 10A may transmit wireless signals to and/or receive wireless signals from radio network node 20A. The wireless signals may contain voice traffic, data traffic, control signals, and/or any other suitable information. In some embodiments, a wireless signal coverage area associated with radio network node 20 may be referred to as a cell 15.

[0152] Wireless device 10 may be any type of wireless device capable of communicating with radio network nodes 20 or with another wireless device/UE 10 over radio signals. Similarly, radio network node 20 may be any type of radio network node capable of communicating with wireless device 10 or with another network node. For example, the term network node may refer to radio network node 20, core network node 30, or even an external node (e.g., third-party node, a node external to the current network), etc. Exemplary embodiments of wireless device 10 are described in more detail below with respect to Figures 8 and 9. Exemplary embodiments from radio network node 20 are discussed below with respect to Figures 10 and 11.

[0153] In certain embodiments, radio network nodes 20 may interconnect with a radio network controller. The radio network controller may control radio network nodes 20 and may provide certain radio resource management functions, mobility management functions, and/or other suitable functions. In certain embodiments, functions of the radio network controller may be included in radio network node 20. The radio network controller may interconnect with a core network node 30. In certain embodiments, the radio network controller may interconnect with core network node 30 through an interconnection network 25.

[0154] Interconnection network 25 may refer to any interconnection system capable of transmitting audio, video, signals, data, messages, or any combination of the foregoing. Interconnection network 125 may include the entire public switched telephone network or a portion of the public switched telephone network (PSTN), a public or private data network, a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), a local, regional, or global computer or communications network such as the Internet, a fixed or wireless network, a corporate intranet, or any other suitable communications link, including combinations thereof.

[0155] In some embodiments, the core network node 30 may manage the establishment of communication sessions and various other functionalities for the wireless devices 10. Examples from the core network node 30 may include mobile switching center (MSC), MME, serving communication gateway (SGW), packet data network gateway (PGW), operation and maintenance (O&M), operations support system (OSS), SON, positioning node (e.g., Enhanced Service Mobile Location Center, E-SMLC), MDT node, etc. The wireless devices 10 may exchange certain signals with the core network node using the non-access stratum layer. In non-access stratum signaling, signals between the wireless devices 10 and the core network node 30 may be passed transparently over the radio access network. In certain embodiments, the radio network nodes 20 may interconnect with one or more network nodes along an inter-node interface. For example, radio network nodes 20A and 20B may interconnect over an X2 interface or an evolution thereof.

[0156] Although Figure 7 illustrates a particular arrangement of the network, the present invention contemplates that various embodiments described herein may be applied to a variety of networks having any suitable configuration. For example, the wireless network may include any suitable number of wireless devices 10 and radio network nodes 20, as well as any suitable additional elements to support communication between the wireless devices or between a wireless device and another communication device (such as a landline telephone). The embodiments may be implemented in any suitable type of telecommunications system supporting any suitable communication standards and using any suitable components, and are applicable to any radio access technology (RAT) or multiple RAT systems in which the wireless device receives and/or transmits signals (e.g., data).

[0157] Figure 8 is a block diagram of a wireless device 10 according to certain embodiments of the present invention. Wireless device 10 may correspond, for example, to the wireless device (or UE) described above. Wireless device 10 includes a wireless interface 12, processing circuitry 14, and memory 16. Wireless interface 12 may comprise a transceiver having certain receiver and transmitter capabilities as described above in conjunction with Figures 1-7. In some embodiments, wireless interface 12 facilitates transmitting wireless signals to and receiving wireless signals from radio network node 20 (e.g., via an antenna), processing circuitry 14 executes instructions to provide some or all of the functionality described herein as being provided by wireless device 10, and memory 16 stores the instructions for execution by processing circuitry 14.

[0158] Processing circuitry 14 may include any suitable combination of hardware and software implemented in one or more modules to execute instructions and manipulate data to perform some or all of the described functions of wireless device 10 (or UE), such as the functions of wireless device 10 (or UE) described above. In some embodiments, processing circuitry 14 may include, for example, one or more computers, one or more central processing units (CPUs), one or more microprocessors, one or more applications, one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), and/or other logic. In certain embodiments, processing circuitry 14 may comprise one or more of the modules discussed below with respect to Figure 9.

[0159] Memory 16 is generally operable to store instructions, such as a computer program, software, an application that includes one or more of logic, rules, algorithms, codes, tables, etc., and/or other instructions capable of being executed by a set of processing circuitry 14. Examples of memory include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard drive), removable storage media (e.g., a Compact Disc (CD) or a Digital Video Disc (DVD)), and/or any other volatile or non-volatile, non-transitory computer-readable, and/or computer-executable memory devices that store information, data, and/or instructions that can be used by the processor of wireless device 10.

[0160] Other embodiments of the wireless device 10 may include additional components beyond those shown in Figure 8 that may be responsible for providing certain aspects of the wireless device functionality, including any functionality described above and/or any additional functionality (including any functionality necessary to support the solution described above). As an example only, the wireless device 10 may include input devices and circuitry, output devices, and one or more synchronization units or circuitry, which may be part of the processor. Input devices include mechanisms for inputting data into the wireless device 10. For example, input devices may include input mechanisms such as a microphone, input elements, a display, etc. Output devices may include mechanisms for outputting data in audio, video, and/or hard copy. For example, output devices may include a speaker, a display, etc.

[0161] Figure 9 is a block diagram illustrating examples of modules that may be included in a wireless device 10 in accordance with certain embodiments of the present invention. In certain embodiments, the wireless device may include any one or more of: receiving module(s) 91, communication module(s) 92, determination module(s) 93, input module(s) 94, display module(s) 95, and/or other suitable modules. The functionality of the modules may be integrated into a single component or separated among multiple components in any suitable manner. In certain embodiments, one or more of the modules may be implemented using the processing circuitry 14 described with respect to Figure 8.

[0162] The determination module 93 may perform the processing functions of the wireless device 10 (including any of the UE functionalities to support the embodiments described above). As an example, the determination module 93 may determine beams on which to perform radio measurements based on one or more beam-related parameters (N) per carrier received from the network node. For example, the determination module 93 may use the beam-related parameter(s) to perform one or more radio measurements on one or more beams of one or more cells operating on the carrier (e.g., F1) associated with the parameter received from the network node.

[0163] The determination module 93 may include or be included in one or more processors, such as the processing circuitry 14 described above with respect to Figure 8. The determination module 93 may include analog and/or digital circuitry configured to perform any of the functions of the determination module 93 and/or processing circuitry 14 described above. The functions of the determination module 93 described above may, in certain embodiments, be performed in one or more distinct modules.

[0164] The communication module 92 may perform the transmission functions of the wireless device 10. As an example, the communication module 92 may report radio measurements to a network node. The communication module 92 may include a transmitter and/or a wireless interface, such as the wireless interface 12 described above with respect to Figure 8. The communication module 92 may include circuitry configured to wirelessly transmit messages and/or signals. In particular embodiments, the communication module 92 may receive messages and/or signals for transmission from the determination module 93. In certain embodiments, the functions of the communication module 93 described above may be performed in one or more distinct modules.

[0165] The receiving module 91 may receive the receiving functions of the wireless device 10. For example, the receiving module 91 may receive the parameter-related beam per carrier (e.g., N11). The receiving module 91 may include a receiver and/or a wireless interface, such as the wireless interface 12 described above with respect to Figure 8. The receiving module 91 may include circuitry configured to wirelessly receive messages and/or signals. In particular embodiments, the receiving module 91 may communicate received messages and/or signals to the determining module 93. The functions of the receiving module 91 described above may, in certain embodiments, be performed in one or more distinct modules.

[0166] The input module 94 may receive user input intended for the wireless device 10. For example, the input module may receive key presses, button presses, taps, swipes, audio signals, video signals, and/or any other appropriate signals. The input module may include one or more keys, buttons, levers, switches, touchscreens, microphones, and/or cameras. The input module may communicate received signals to the determination module 93. The functions of the input module 94 described above may, in certain embodiments, be performed in one or more distinct modules.

[0167] The display module 95 may present signals to a display of the wireless device 10. The display module 95 may include the display and/or any appropriate circuitry and hardware configured to present signals to the display. The display module 95 may receive signals for presentation to the display from the determination module 95. The functions of the display module 95 described above may, in certain embodiments, be performed in one or more distinct modules.

[0168] The determination module 93, the communication module 92, the receiving module 91, the input module 94, and the display module 95 may include any suitable hardware and/or software configuration. The wireless device 10 may include additional modules beyond those shown in Figure 9 that may be responsible for providing any suitable functionality, including any of the functionalities described above and/or any of the additional functionalities (including any functionality necessary to support the various solutions described herein).

[0169] Figure 10 is a block diagram from the network node (e.g., radio network node 20) according to certain embodiments of the present invention. As discussed above, a radio network node 20 is an example from the network node. The radio network node 20 may include one or more of a wireless interface 22, processing circuitry 24, memory 26, and network interface 28. The wireless interface 22 may comprise a transceiver having receiver and transmitter capabilities. In some embodiments, wireless interface 22 facilitates transmitting wireless signals to and receiving wireless signals from wireless device 10 (e.g., through an antenna), processing circuitry 24 executes instructions to provide some or all of the functionality described above as being provided by radio network node 20 (or, more generally, as being provided by a network node), memory 26 stores the instructions for execution by processing circuitry 24, and network interface 28 communicates signals to backend network components, such as a communications gateway, switch, router, Internet, Public Switched Telephone Network (PSTN), network nodes 30 or core radio network controllers, etc.

[0170] Processing circuitry 24 may include any suitable combination of software hardware implemented in one or more modules to execute instructions and manipulate data to perform some or all of the functions described from radio network node 20 (or, more generally, from the network node), such as those functions described above. As an example, processing circuitry 24 may execute instructions and manipulate data to perform any of the methods described above, such as methods in which a network node determines at least one parameter N per carrier frequency (where parameter N indicates a maximum number of beams to be used by a wireless device for signal measurements in a cell) and communicates the parameter(s) N to the wireless device. In some embodiments, processing circuitry 24 may include, for example, one or more computers, one or more central processing units (CPUs), one or more microprocessors, one or more applications, one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), and/or other logic elements. In certain embodiments, processing circuitry 24 may comprise one or more of the modules discussed below with respect to Figure 11.

[0171] Memory 26 is generally operable to store instructions such as a computer program, software, an application including one or more of logic, rules, algorithms, code, tables, etc., and/or other instructions capable of being executed by a processing circuitry 24. Examples of memory 26 include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard drive), removable storage media (e.g., a Compact Disc (CD) or a Digital Video Disc (DVD)), and/or any other volatile or non-volatile non-transitory computer-readable and/or computer-executable memory devices that store information.

[0172] In some embodiments, network interface 28 is communicatively coupled to processing circuitry 24 and may refer to any suitable device operable to receive input to radio network node 20, send output from radio network node 20, perform suitable processing of the input or output or both, communicate to other devices, or any combination of the foregoing. Network interface 28 may include appropriate hardware (e.g., port, modem, network interface card, etc.) and software, including protocol conversion and data processing capabilities, to communicate over a network.

[0173] Other embodiments of the radio network node 20 may include additional components beyond those shown in Figure 10 that may be responsible for providing certain aspects of the access node functionality, including any of the functionality described above and/or any additional functionality (including any functionality necessary to support the solutions described above). The various different types of access nodes may include components that have the same physical hardware but configured (e.g., through programming) to support different radio access technologies, or may represent partially or completely different physical components.

[0174] Processors 24, interfaces 22, 25, and/or 28, and memory 26 similar to those described with respect to Figure 10 may be included in other network nodes (such as core network node 30). Other network nodes may optionally include a wireless or non-wireless interface (such as wireless interface 22 described in Figure 10).

[0175] Figure 11 is a block diagram illustrating examples of modules that may be included in a network node, such as radio network node 20 or core network node 30, in accordance with certain embodiments of the present invention. In certain embodiments, radio network node 20 may include any one or more of: receiving module(s) 1102, communication module(s) 1104, determination module(s) 1106, and/or other suitable modules. The functionality of the modules may be integrated into a single component or separated among multiple components in any suitable manner. In certain embodiments, one or more of the modules may be implemented using the processing circuitry 24 described with respect to Figure 10.

[0176] The determination module 1106 may perform the processing functions from the network node 20 (including any network node functionality to support the embodiments described above). As an example, the determination module 1106 may determine information about a common parameter (N) per carrier frequency that informs the UE about a maximum number of beams, on whose signals the UE may perform measurements in any cell on the indicated carrier.

[0177] The determination module 1106 may include or be included in one or more processors, such as the processing circuitry 24 described above with respect to Figure 10. The determination module 1106 may include analog and/or digital circuitry configured to perform any of the functions of the determination module 1106 and/or the processing circuitry 14 described above. The functions of the determination module 1106 described above may, in certain embodiments, be performed in one or more distinct modules.

[0178] The communication module 1104 may perform transmission functions from the network node 20. As an example, the communication module 1104 may send information about a common parameter (N) per carrier frequency that informs the UE about a maximum number of beams, on whose signals the UE may perform measurements in any cell on the indicated carrier. The communication module 1104 may include a transmitter and/or a wireless interface, such as the wireless interface 22 described above with respect to Figure 10. As a further example, the communication module 1104 may send information to other network nodes 20, such as information about specific cell offsets for N on the different carriers. The communication module 1104 may include a network interface, such as the interface 28 described above with respect to Figure 10. The communication module 1104 may include circuitry configured to transmit messages and/or signals wirelessly and/or wireline. In particular embodiments, communication module 1104 may receive messages and/or signals for transmission from determination module 1106. In certain embodiments, the functions of communication module 1106 described above may be performed in one or more distinct modules.

[0179] The receiving module 1102 may perform receiving functions from the network node 20. For example, the receiving module 1102 may receive measurement reports from the wireless device 10. The receiving module 1102 may include a receiver and/or a wireless interface, such as the wireless interface 22 described above with respect to Figure 10. As another example, the receiving module may receive information from other network nodes 20, such as information about specific cell offsets for N on the different carriers. The receiving module 1102 may include a network interface, such as the interface 28 described with respect to Figure 10. The receiving module 1102 may include circuitry configured to receive wireless and/or wireline messages and/or signals. In particular embodiments, the receiving module 1102 may communicate received messages and/or signals to the determining module 1106. The functions of the receiving module 1102 described above may, in certain embodiments, be performed in one or more distinct modules.

[0180] Example embodiments are provided below. The examples may be implemented using any of the components discussed above and may be combined with any other of the embodiments discussed above in any suitable manner. Exemplary embodiments 1 and 10 are illustrated in Figures 12 and 13 respectively.

[0181] 1. A method for use at a network node, the method comprising:

[0182] determine (1202) at least one parameter N per carrier frequency, wherein the parameter N indicates a number of beams to be used by a wireless device for signal measurements in a multi-beam cell; and

[0183] communicate (1204) the N parameter to the wireless device.

[0184] 2. The method of exemplary embodiment 1, further comprising:

[0185] receive, from one or more other network nodes, information about specific cell offsets for parameter N on different carriers; and

[0186] use the information received when determining the parameter N.

[0187] 3. The method of exemplary embodiment 1, further comprising:

[0188] receive, from one or more other network nodes, information about a number of beams used in each respective network node cell; and

[0189] use the received information and information about the number of beams used in the network node cells themselves to determine a common parameter N for all cells on a carrier.

[0190] 4. A network node (20) comprising:

[0191] the processing circuitry (24) operable to determine at least one parameter N per carrier frequency, wherein the parameter N indicates a number of beams to be used by a wireless device (10) for signal measurements in a multi-beam cell; and

[0192] an interface (25) operable to communicate the N parameter to the wireless device.

[0193] 5. The network node of exemplary embodiment 4 further operable to:

[0194] receive, from one or more other network nodes, information about specific cell offsets for parameter N on different carriers; and

[0195] use the information received when determining the parameter N.

[0196] 6. The network node of exemplary embodiment 4 further operable to:

[0197] receive, from one or more other network nodes, information about a number of beams used in each respective network node cell; and

[0198] use the received information and information about the number of beams used in the network node cells themselves to determine a common parameter N for all cells on a carrier.

[0199] 7. A computer program product comprising a non-transitory computer-readable storage medium (26) having computer-readable program code embedded in the medium that, when executed by the processing circuitry (24) from the network node (20), causes the network node to perform operations comprising:

[0200] determining at least one parameter N per carrier frequency, wherein the parameter N indicates a number of beams to be used by a wireless device for signal measurements in a multi-beam cell; and

[0201] communicate the N parameter to the wireless device.

[0202] 8. The computer program product of exemplary embodiment 7, the operations further comprising:

[0203] receive, from one or more other network nodes, information about specific cell offsets for parameter N on different carriers; and

[0204] use the information received when determining the parameter N.

[0205] 9. The computer program product of exemplary embodiment 7, the operations further comprising:

[0206] receive, from one or more other network nodes, information about a number of beams used in each respective network node cell; and

[0207] use the received information and information about the number of beams used in the network node cells themselves to determine a common parameter N for all cells on a carrier.

[0208] 10. A method for use in a wireless device, the method comprising:

[0209] receive (1302) from the network node at least one parameter N per carrier frequency, wherein the parameter N indicates a number of beams to be used by a wireless device for signal measurements in a multi-beam cell; and

[0210] use (1304) the at least one parameter N.

[0211] 11. A wireless device (10), comprising:

[0212] an interface (12) operable to receive, from the network node (20), at least one parameter N per carrier frequency, wherein the parameter N indicates a number of beams to be used by a wireless device for signal measurements in a multi-beam cell; and

[0213] the processing circuitry (14) operable to use the at least one parameter N.

[0214] 12. A computer program product comprising a non-transitory computer-readable storage medium (16) having computer-readable program code embedded on the medium that, when executed by the processing circuitry (14) from the network node (10), causes the wireless element to perform operations comprising:

[0215] receive from the network node at least one parameter N per carrier frequency, wherein the parameter N indicates a number of beams to be used by a wireless device for signal measurements in a multi-beam cell; and

[0216] use at least one parameter N.

[0217] Figures 14A-C illustrate example signal flows in which a wireless device 10 receives at least one N parameter per carrier frequency from network node 20A in accordance with certain embodiments. In certain embodiments, a network node 20A (such as a network node comprising a serving cell serving wireless device 10) performs a method comprising steps 1402 and 1404 (e.g., 1404A, B, or C). In certain embodiments, a wireless device performs a method comprising steps 1404 (e.g., 1404A, B, or C), 1406, and optionally, step 1408.

[0218] In step 1402, network node 20A determines at least one parameter N per carrier frequency. Parameter N indicates a maximum number of beams to be used by a wireless device for signal measurements in a cell. Network node 20A may determine parameter(s) N in order to assist wireless device 10 when performing signal measurements in cells belonging to the same carrier frequency and/or when performing signal measurements in a multi-beam cell.

[0219] In step 1404, network node 20A communicates the one or more parameters (N) determined in step 1402 to wireless device 10. The parameter(s) N may be communicated in system information common to all wireless devices or in dedicated signaling for wireless device 10. In certain embodiments, the parameter(s) N is signaled from the network node to the wireless device in a measurement object information element (MeasObject).

[0220] Figures 14A, B, and C each illustrate an example of an option for communicating the N parameter(s) to the wireless device 10. Figure 14A illustrates an example in which the network node 20A communicates an N parameter and an indicator indicating that all carrier frequencies use the same N parameter (e.g., step 1404A). Figure 14B illustrates an example in which the network node 20A communicates a first N1 parameter and an indicator indicating which carrier frequencies use the first N1 parameter (e.g., step 1404B). For example, the indicator may indicate the use of the first N1 parameter for both the first carrier frequency and the second carrier frequency. Figure 14C illustrates an example in which the network node 20A communicates different N parameters for different carrier frequencies. For example, the network node communicates a first parameter N1 and information associating the first parameter N1 with a first carrier frequency as well as a second parameter N2 and information associating the second parameter N2 with a second carrier frequency (e.g., step 1404C). The second carrier frequency is different from the first carrier frequency. In some embodiments, the information associating the first parameter N1 with the first carrier frequency comprises a frequency channel number of the first carrier frequency. Similarly, the information associating the second parameter N2 with the second carrier frequency comprises a frequency channel number of the second carrier frequency.

[0221] The wireless device 10 receives the N parameter(s) in step 1404 and uses the N parameter(s) in step 1406. For example, in certain embodiments, the N parameter(s) corresponding to a particular carrier frequency is used to determine the maximum number of beams to be used to perform signal measurements in the cell (step 1406A) and perform signal measurements up to the maximum number of beams in the cell (step 1406B). The cell in which the signal measurements are performed may be a serving cell (e.g., a cell of network node 20A) or a neighboring cell (e.g., a cell of another network node). Examples of types of signal measurements that the wireless device 10 may perform include cell-specific reference signal measurements, synchronization signal measurements, or radio resource management (RRM) measurements.

[0222] In certain embodiments, the at least one parameter N per carrier frequency comprises a first parameter N1 and a second parameter N2. The first parameter N1 is to perform a first type of signal measurements on a first carrier frequency. The second parameter N2 is to perform a second type of signal measurements on the same carrier frequency (i.e., the first carrier frequency). The second type of signal measurements is different from the first type of signal measurements. As an example, the first parameter N1 may be configured to perform synchronization signal measurements on the first frequency, and the second parameter N2 may be configured to perform cell-specific reference signal measurements on the same frequency (i.e., the first frequency). The first and second parameters N may be configured such that the wireless device performs synchronization signal measurements on more beams and cell-specific reference signal measurements on fewer beams, or vice versa.

[0223] Figures 14A-C each include an optional step 1408 in which the wireless device 10 performs one or more tasks based on the signal measurements performed in step 1406B. Examples of tasks include deriving a cell signal quality, deriving a cell signal strength, reporting to the network node, reporting to a neighboring network node, reporting to another wireless device, changing a cell, positioning the wireless device, performing drive test minimization, and/or performing power control.

[0224] As discussed above, the parameter(s) N are provided per carrier frequency. Providing parameter(s) N per carrier can reduce complexity that may otherwise be required if the parameter(s) N are provided per cell. For example, if the parameter(s) N are provided per cell, the wireless device 10 would need to know information for each cell and a list of neighboring cells. In the present invention, providing parameter(s) N per carrier frequency reduces this complexity and can allow for more consistent measurements due to a carrier frequency having similar dissipation characteristics from one cell to the next.

[0225] Figures 15-16 illustrate example signal flows in which a network node (such as network node 20A discussed in connection with Figures 14A-C) determines a common parameter N for all cells on a particular carrier frequency in accordance with certain embodiments. In the example of Figure 15, network node 20A receives information from one or more other network nodes in step 1502. The information indicates a number of beams that each respective network node's cell uses for a particular carrier frequency. In the example of Figure 15, network node 20A receives information from network node 20B about the number of beams that a cell from network node 20B uses for a particular carrier frequency. In step 1504, network node 20A uses the received information (number of beams a cell from network node 20B uses for a particular frequency) and information about the number of beams used in network node 20A's own cell for the particular carrier frequency to determine a common parameter N for all cells on the particular carrier frequency.

[0226] In the example of Figure 16, network node 20A receives information about the N parameters that other network nodes use for a particular carrier frequency. In particular, in the example shown in Figure 16, network node 20A receives information in step 1602 about the N parameter that a cell from network node 20B uses for a particular carrier frequency. In step 1604, network node 20A uses the received information (the N parameter that a cell from network node 20B uses for a particular carrier frequency) and the information about the N parameter used in network node 20A's own cell for the particular carrier frequency to determine a common N parameter for all cells on the particular carrier frequency.

[0227] In certain embodiments, the common parameter N is determined based on one of the following: maximum parameter N used by the network node or any of the other network nodes, minimum parameter N used by the network node or any of the other network nodes, average of parameters N used by the network node and the other network nodes, or X-th percentile of parameters N used by the network node and the other network nodes.

[0228] Figures 17-18 illustrate example signal flows in which network node 20A indicates to wireless device 10 whether all cells in a group of cells belonging to a particular carrier frequency have the same number of beams in accordance with certain embodiments. For example, in Figure 17, network node 20A indicates that all cells in a group of cells belonging to a particular carrier frequency have the same number of beams in step 1702. Wireless device 10 receives the indication in step 1702 and, in response, detects the number of beams on the particular carrier frequency for any cell in the group (step 1704) and considers that the other cells in the group have the same number of beams on the particular carrier frequency (step 1706). As an example, the wireless device 10 may detect that the serving cell has four beams on a first carrier frequency and may then consider that a neighboring cell in the group also has four beams on the first carrier frequency.

[0229] Referring to Figure 18, network node 20A indicates that all cells in a cell group belonging to a particular carrier frequency do not have the same number of beams in step 1802. Wireless device 10 receives the indication in step 1802 and, in response, detects the number of beams on the particular carrier frequency in a cell by reading system information of the respective cell. As an example, wireless device 10 may read system information of the serving cell and system information of a neighboring cell in order to detect that the serving cell has four beams on a first carrier and the neighboring cell has eight beams on the first carrier.

[0230] Figures 19-20 illustrate example signal flows in which network node 20A indicates to wireless device 10 whether the number of beams in cells belonging to a first carrier frequency is the same as the number of beams in cells belonging to a second carrier frequency in accordance with certain embodiments. For example, in step 1902 of Figure 19, network node 20A communicates an indicator indicating that the number of beams in cells belonging to a first carrier frequency is the same as the number of beams in cells belonging to a second carrier frequency. Wireless device 10 receives the indicator in step 1902 and, in response, detects the number of beams in the first carrier frequency in step 1904. In step 1906, the wireless device considers that the second carrier frequency has the same number of beams. As an example, the wireless device 10 may detect four beams on the first carrier frequency and may then consider that the second carrier frequency also has four beams.

[0231] Referring to Figure 20, network node 20A communicates an indicator at step 2002 that indicates that the number of beams in cells belonging to the first carrier frequency is not the same as the number of beams in cells belonging to the second carrier frequency. Wireless device 20 receives the indicator at step 2002, and in response, the wireless device detects the number of beams on the first carrier frequency (step 2004) and detects the number of beams on the second carrier frequency (step 2006) (instead of assuming that the second carrier frequency has the same number of beams).

[0232] Figure 21 illustrates an example of a signal flow in which a wireless device 10 is configured with a specific UE offset in accordance with certain embodiments. In step 2102, the network node 20A determines a specific UE offset based on the beamforming capabilities of the wireless device. In step 2104, the network node 20A sends the specific UE offset to the wireless device 10. The wireless device 10 receives the specific UE offset in step 2104. In step 2106, the wireless device 10 is configured with the specific UE offset. For example, the wireless device 10 may set a configuration parameter based on the specific UE offset. In step 2108, the wireless device 10 adjusts the value of the at least one parameter N in accordance with the specific UE offset. As an example, if the UE-specific offset is set to +1 and the N parameter is set to 3, the wireless device 10 sets the value of the N parameter that it uses to perform signal measurements to 4.

[0233] Figures 22-24 illustrate example signal flows regarding cell-specific offsets in accordance with certain embodiments. With respect to Figure 22, in step 2202, network node 20A communicates one or more cell-specific offsets to wireless device 10. Each cell-specific offset is associated with a specific cell. For example, a cell-specific offset may be associated with a serving cell from network node 20A and/or another cell-specific offset may be associated with a neighboring cell from another network node (such as network node 20B). The wireless device receives the cell-specific offset (or cell-specific offsets) in step 2202, and in step 2204, wireless device 10 is configured with the cell-specific offset (or cell-specific offsets). For example, wireless device 10 may set one or more configuration parameters based on the cell-specific offset (or cell-specific offsets). In step 2206, the wireless device 10 adjusts the value of the at least one parameter N according to the cell-specific offset when performing signal measurements of the specific cell. As an example, if the cell-specific offset for the serving cell is set to +1 and the parameter N is set to 3 for the relevant carrier frequency, the wireless device 10 adjusts the value of the parameter N such that the wireless device 10 uses a value of 4 as the maximum number of beams for signal measurements of the relevant carrier frequency of the serving cell.

[0234] Figure 23 illustrates an example in which network node 20A receives information in step 2302 about cell-specific offsets for parameter N at different carrier frequencies. The information is received from one or more other network nodes, such as network node 20B. In step 2304, network node 20A uses the received information in determining at least one N parameter per carrier frequency. In some embodiments, network node 20A may determine to send wireless device 10 a smaller N parameter for larger cell-specific offsets and a larger N parameter for smaller cell-specific offsets.

[0235] Figure 24 illustrates an example in which wireless device 10 detects the cell-specific offset of a new cell, such as a new cell from network node 20B, in step 2402. In step 2404, wireless device 10 reports the cell-specific offset of the new cell to the serving cell (e.g., a cell from network node 20A). Network node 20A/serving cell receives the cell-specific offset of the new cell in step 2404. Optionally, network node 20A/serving cell uses the cell-specific offset of the new cell in step 2406 to determine at least one parameter N for a carrier frequency.

[0236] Any two or more embodiments described in this document may be combined with each other in any way. Additionally, the described embodiments are not limited to the radio access technologies described. That is, the described embodiments may be adapted to other radio access technologies.

[0237] Modifications, additions, or omissions may be made to the systems and apparatus described herein without departing from the scope of the invention. The components of the systems and apparatus may be integrated or separate. Furthermore, the operations of the systems and apparatus may be performed by more, fewer, or other components. Additionally, the operations of the systems and apparatus may be performed using any suitable logic element comprising software, hardware, and/or other logic element. As used herein, “each” refers to each member of a set or each member of a subset of a set. It is noted that the language “operable to perform an action” may include “adapted to perform the action.”

[0238] Modifications, additions, or omissions may be made to the methods described herein without departing from the scope of the invention. The methods may include more, fewer, or other steps. Additionally, the steps of any method described herein are not to be performed in the exact order disclosed unless explicitly stated. While certain steps are described as optional for certain embodiments, other steps could be optional in other embodiments. All references to "a/an/the" element, apparatus, component, step, etc. should be broadly construed as referring to at least one instance of the element, apparatus, component, step, etc., unless otherwise stated.

[0239] Although this invention has been described in terms of certain embodiments, changes and permutations of the embodiments will be apparent to those skilled in the art. Accordingly, the above description of the embodiments does not restrict this invention. Other changes, substitutions, and alterations are possible without departing from the scope of this invention.

[0240] 3GPP specifications such as Rxxxx documents and TSxxx documents are publicly available at www.3gpp.org.

Claims (13)

1. A method for use at a network node, the method comprising: determining (1202, 1402) a first parameter associated with a first carrier frequency and a second parameter associated with a second carrier frequency, wherein each of the first and second parameters indicates a maximum number of beams to be used by a wireless device for cell quality derivation; communicating (1204, 1404A, 1404B, 1404C) the first and second parameters to the wireless device. 2. Method according to claim 1, characterized in that the first and second parameters are communicated in dedicated signaling to the wireless device. 3. Method according to claim 1, characterized in that the first parameter is communicated in a first measurement object information element, MeasObject. 4. The method of claim 1, wherein the first carrier frequency is indicated in terms of a first frequency channel number. 5. The method of claim 1, wherein the cell quality derivation includes using the first parameter to perform measurement of synchronization signals at the first carrier frequency and the second parameter to perform measurement of synchronization signals at the second carrier frequency. 6. A network node (20) comprising: a processing circuitry (24) operable to determine a first parameter associated with a first carrier frequency and a second parameter associated with a second carrier frequency, wherein each of the first and second parameters indicates a maximum number of beams to be used by a wireless device for cell quality derivation; and a wireless interface (22) operable to communicate the first and second parameters to the wireless device. 7. A method for use in a wireless device, the method comprising: receiving (1302, 1404A, 1404B, 1404C) from a network node a first parameter associated with a first carrier frequency and a second parameter associated with a second carrier frequency, wherein each of the first and second parameters indicates a maximum number of beams to be used by the wireless device for cell quality derivation; and using (1304, 1406) the first parameter to perform cell quality derivation based on measurement of synchronization signals on the first carrier frequency and the second parameter to perform cell quality derivation based on measurement of synchronization signals on the second carrier frequency. 8. The method of claim 7, wherein the first and second parameters are received in signaling dedicated to the wireless device. 9. The method of claim 7, wherein the first parameter is received in a first measurement object information element, MeasObject. 10. The method of claim 7, wherein the first carrier frequency is indicated in terms of a first frequency channel number. 11. The method of claim 7, wherein the wireless device uses the first parameter to perform cell quality derivation on any cell operating at the first carrier frequency. 12. The method of claim 7, further comprising: detecting at least one cell operating at the first carrier frequency; and using the first parameter to derive the cell quality for the at least one detected cell. 13. A wireless device (10) comprising: an interface (12) operable to receive, from a network node, a first parameter associated with a first carrier frequency and a second parameter associated with a second carrier frequency, wherein each of the first and second parameters indicates a maximum number of beams to be used by the wireless device for cell quality derivation; and a processing circuitry (14) operable to use the first parameter to perform cell quality derivation based on measurement of synchronization signals on the first carrier frequency and the second parameter to perform cell quality derivation based on measurement of synchronization signals on the second carrier frequency.