WO2018203804A1 - Methods for reducing cell search time under coverage enhancement - Google Patents

Abstract

Systems and methods are disclosed for reducing a system acquisition delay in a cellular communications network, e.g., for Machine Type Communication (MTC) operation under coverage enhancement. In some embodiments, a method of operation of a wireless device (102) in a wireless communication network (100) comprises obtaining (204, 704, 706) information related to a relationship between one or more parameters between cells of two or more Radio Access Technologies (RATs), wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT. The method further comprises performing (206, 708) one or more tasks based on the information.

Description

METHODS FOR REDUCING CELL SEARCH TIME UNDER COVERAGE

ENHANCEMENT

Related Applications

[0001] This application claims the benefit of provisional patent application serial number 62/502, 105; filed May 5, 2017 and provisional patent application serial number 62/502, 123, filed May 5, 2017, the disclosures of which are hereby incorporated herein by reference in their entireties. Technical Field

[0002] Further Enhancements for Machine Type Communication (FeMTC), Radio Resource Management (RRM), intra-frequency measurement gaps, positioning Background

Machine Type Communication (MTC) / enhanced MTC (eMTC) / Further

Enhancements for MTC (FeMTC)

[0003] MTC devices are expected to be of low cost and low complexity. A low complexity User Equipment device (UE) envisage for Machine-to-Machine (M2M) operation may implement one or more low cost features like smaller downlink and uplink maximum transport block size (e.g., 1000 bits) and/or reduced downlink channel bandwidth of 1 .4 megahertz (MHz) for data channel (e.g., Physical Downlink Shared Channel (PDSCH)). A low cost UE may also comprise of a half-duplex (Half Duplex Frequency Division Duplexing (HD-FDD)) and one or more of the following additional features: single receiver (1 Rx) at the UE, smaller downlink and/or uplink maximum transport block size (e.g., 1000 bits), and reduced downlink channel bandwidth of 1 .4 MHz for data channel. The low cost UE may also be termed a low complexity UE.

[0004] The path loss between an M2M device and the base station can be very large in some scenarios such as when used as a sensor or metering device located in a remote location such as in the basement of the building. In such scenarios, reception of the signal from the base station is very challenging. For example, the path loss can be worse than 20 decibels (dB) compared to normal cellular network operation. In order to cope with such challenges, the coverage in uplink and/or in downlink has to be substantially enhanced. This is realized by employing one or a plurality of advanced techniques in the UE and/or in the radio network node for enhancing the coverage. Some non-limiting examples of such advanced techniques are (but are not limited to) transmit power boosting, repetition of the transmitted signal, applying additional redundancy to the transmitted signal, use of an advanced/enhanced receiver, etc. In general, when employing such coverage enhancing techniques, the M2M is regarded to be operating in 'coverage enhancing mode.'

[0005] A low complexity MTC UE (e.g., a UE with 1 Rx and/or limited bandwidth (BW)) may also be capable of supporting enhanced coverage mode of operation, also known as Coverage Enhanced Mode B (CEModeB). The normal coverage mode of operation is also called Coverage Enhanced Mode A

(CEModeA).

Configuration of Coverage Enhancement (CE) Level

[0006] The eMTC or FeMTC UE can be configured via Radio Resource Control (RRC) with one of the two possible coverage modes, i.e. CEModeA or CEModeB. These are also sometimes referred to as CE levels. CEModeA and CEModeB are associated with a different number of repetitions used in downlink and/or uplink physical channels as signaled in the following RRC message in Third Generation Partnership Project (3GPP) Technical Specification (TS) 36.331 V13.3.2.

p sc -max um epet t on mo e n cates t e set o repet t on num ers

pusch-maxNumRepetitionCEmodeB indicates the set of PUSCH repetition numbers

[0007] If the UE is not configured in any of CEModeA and CEModeB then, according to 3GPP TS 36.21 1 V13.2.0, the UE shall assume the following CE level configuration:

- If the Physical Random Access Channel (PRACH) CE level is 0 or 1 , then the UE shall assume CEModeA; or

- If the PRACH CE level is 2 or 3, then UE shall assume CEModeB.

[0008] The UE determines one of the four possible CE levels (0, 1 , 2, and 3) during the random access procedure by comparing the downlink radio measurement (e.g., Reference Signal Received Power (RSRP)) with the one or more thresholds signaled to the UE by the network node.

Summary

[0009] Systems and methods are disclosed for reducing a system acquisition delay in a cellular communications network, e.g., for Machine Type

Communication (MTC) operation under Coverage Enhancement (CE). In some embodiments, a method of operation of a wireless device in a wireless communication network comprises obtaining information related to a relationship between one or more parameters between cells of two or more Radio Access Technologies (RATs), wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT. The method further comprises performing one or more tasks based on the information.

[0010] In some embodiments, the information related to the relationship between the one or more parameters between the cells of the two or more RATs comprises information indicating per carrier information on a cell identity (ID) relation of the two or more RATs. Using this information, system as well as wireless device performance can be improved by allowing the wireless device which is capable of receiving signals from a multiple RATs to improve the system acquisition time of one RAT based on the information regarding the per carrier information on a cell ID relation of that RAT and the other RAT.

[0011] In some embodiments, obtaining the information related to the relationship between the one or more parameters between the cells of the two or more RATs comprises receiving the information indicating per carrier information on the cell ID relation of the two or more RATs, and performing the one or more tasks based on the information comprises adapting a measurement procedure for performing measurements on at least one cell of the first RAT and/or at least one cell of the second RAT based on the per carrier information on the cell ID relation of the two or more RATs. Further, in some embodiments, adapting the measurement procedure comprises adapting the measurement procedure for performing measurements on: at least one cell of the first RAT based on the information indicating the per carrier information on the cell ID relation of the two or more RATs and signals received on at least one cell of the second RAT, and/or at least one cell of the second RAT based on the information indicating the per carrier information on the cell ID relation of the two or more RATs and signals received on at least one cell of the first RAT.

[0012] In some embodiments, the per carrier information on the cell ID relation of the two or more RATs comprises a per carrier indicator that indicates whether cells of the first RAT that are operating on a carrier of the first RAT and respective cells of the second RAT that are operating within a bandwidth of the carrier of the first RAT have the same cell ID.

[0013] In some embodiments, the per carrier information on the cell ID relation of the two or more RATs comprises a per carrier indicator that indicates, for each of one or more sets of cells each comprising a first cell of the first RAT that is operating on a carrier of the first RAT and a respective second cell of the second RAT that is operating within a bandwidth of the carrier of the first RAT, whether the first cell and the respective second cell have the same cell ID.

Further, in some embodiments, the per carrier indicator is an indication that indicates whether cells of the first RAT that are operating on the carrier of the first RAT and respective cells of the second RAT that are operating in-band or within a guard band of the carrier of the first RAT have the same cell ID. In some other embodiments, the per carrier indicator is an indication that indicates whether cells of the first RAT that are operating on the carrier of the first RAT and respective cells of the second RAT that are operating in-band, within a guard band, or in-band or within a guard band of the carrier of the first RAT have the same cell ID.

[0014] In some embodiments, the per carrier information on the cell ID relation of the two or more RATs comprises a per carrier indicator that indicates an offset between cells IDs of cells of the first RAT that are operating on a carrier of the first RAT and respective cells of the second RAT that are operating within the bandwidth of the carrier of the first RAT.

[0015] In some embodiments, the per carrier information on the cell ID relation of the two or more RATs comprises a per carrier indicator that indicates, for each of one or more sets of cells each comprising a first cell of the first RAT that is operating on a carrier of the first RAT and a respective second cell of the second RAT that is operating within a bandwidth of the carrier of the first RAT, an offset between a cell IDs of first cell and the respective second cell.

[0016] In some embodiments, the per carrier information on the cell ID relation of the two or more RATs comprises information that indicates that cell IDs of cells of the first RAT that operate on a carrier of the first RAT are the same as cell IDs of the second RAT that operate within the bandwidth of the carrier of the first RAT. Further, in some embodiments, adapting the measurement procedure comprises performing cell identification of: a cell on the carrier of the first RAT using a combination of signals received from one or more cells of the first RAT operating on the carrier of the first RAT and signals received from one or more cells of the second RAT that are operating in the bandwidth of the carrier of the first RAT, and/or a cell of the second RAT using a combination of signals received from one or more cells of the first RAT operating on the carrier of the first RAT and signals received from one or more cells of the second RAT that are operating in the bandwidth of the carrier of the first RAT. [0017] In some embodiments, the per carrier information on the cell ID relation of the two or more RATs comprises information that indicates a cell offset between cell IDs of cells operating on a carrier of the first RAT and cell IDs of cells of the second RAT that operate within the bandwidth of the carrier of the first RAT. Further, in some embodiments, adapting the measurement procedure comprises performing cell identification of one or more cells of the first RAT operating on the carrier of the first RAT, and applying the cell offset to cell IDs identified for the one or more cells of the first RAT operating on the carrier of the first RAT to thereby obtain cell IDs of one or more respective cells of the second RAT that are operating within the bandwidth of the carrier of the first RAT. In some other embodiments, adapting the measurement procedure comprises performing cell identification of one or more cells of the second RAT operating within the bandwidth of the carrier of the first RAT, and applying the cell offset to cell IDs identified for the one or more cells of the second RAT operating within the bandwidth of the carrier of the first RAT to thereby obtain cell IDs of one or more respective cells of the first RAT that are operating on the carrier of the first RAT.

[0018] In some embodiments, the method further comprises determining whether the wireless device is capable of receiving signals of multiple RATs.

[0019] In some embodiments, the method further comprises determining whether a serving or camping network node is managing multiple RATs.

[0020] In some embodiments, obtaining the information related to the relationship between one or more parameters between cells of the two or more RATs comprises obtaining first information related to a relation between a CE level of the cells of the two or more RATs and obtaining second information related to a relation between System Frame Numbers (SFNs) of cells of the two or more RATs, and performing the one or more tasks based on the information comprises acquiring system information of: one or more first cells of the first RAT, and/or one or more cells of the second RAT that operate within a

bandwidth of the one or more first cells of the first RAT based on the first information and the second information. [0021] In some embodiments, acquiring the system information comprises acquiring the system information of the one or more first cells of the first RAT and/or the one or more cells of the second RAT that operate within the bandwidth of the one or more first cells of the first RAT using different procedures

depending on the content of the first information and the second information.

[0022] In some embodiments, determining that the first information indicates that a CE level of a second cell of the second RAT is better than a CE level of a first cell of the first RAT, where the second cell of the second RAT operates within a bandwidth of the first cell of the first RAT, determining that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are the same and/or comprises additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT, and acquiring system information comprises acquiring system information of the second cell of the second RAT and using the system information of the second cell of the second RAT to determine at least part of system information of the first cell of the first RAT.

[0023] In some embodiments, determining that the first information indicates that a CE level of a second cell of the second RAT is better than a CE level of a first cell of the first RAT, where the second cell of the second RAT operates within a bandwidth of the first cell of the first RAT, determining that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are not the same and comprises no additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT, and acquiring system information comprises directly acquiring system information of the first cell of the first RAT.

[0024] In some embodiments, determining that the first information indicates that a CE level of a second cell of the second RAT is not better than a CE level of a first cell of the first RAT, where the second cell of the second RAT that operates within a bandwidth of the first cell of the first RAT, and acquiring system information comprises directly acquiring system information of the first cell of the first RAT. [0025] In some embodiments, determining that the first information indicates that a CE level of a first cell of the first RAT is better than a CE level of a second cell of the second RAT that operates within a bandwidth of the first cell, determining that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are the same and/or comprises additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT, and acquiring system information comprises acquiring system information of the first cell of the first RAT and using the system information of the first cell of the first RAT to determine at least part of system information of the second cell of the second RAT.

[0026] In some embodiments, determining that the first information indicates that a CE level of a first cell of the first RAT is better than a CE level of a second cell of the second RAT that operates within a bandwidth of the first cell, determining that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are not the same and comprises no additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT, and acquiring system information comprises directly acquiring system information of the second cell of the second RAT.

[0027] In some embodiments, determining that the first information indicates that a CE level of a first cell of the first RAT is not better than a CE level of a second cell of the second RAT that operates within a bandwidth of the first cell and acquiring system information comprises directly acquiring system information of the second cell of the second RAT.

[0028] Embodiments of a wireless device adapted to perform any one of the aforementioned embodiments of a method of operation of a wireless device are also disclosed.

[0029] In some embodiments, a wireless device for a wireless communication network comprises at least one transceiver and circuitry associated with the at least one transceiver operable to obtain information related to a relationship between one or more parameters between cells of two or more RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT, and perform one or more tasks based on the information.

[0030] Embodiments of a method of operation of a network node in a wireless communication network are also disclosed. In some embodiments, a method of operation of a network node in a wireless communication network comprises providing, to one or more wireless devices, information related to a relationship between one or more parameters between cells of two or more RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT.

[0031] In some embodiments, the information related to the relationship between the one or more parameters between the cells of the two or more RATs comprises information indicating per carrier information on a cell ID relation of the two or more RATs.

[0032] In some embodiments, the method further comprises determining a relation between cell IDs of cells of the first RAT that operate on a carrier of the first RAT and cell IDs of cells of the second RAT that operate within a bandwidth of the carrier of the first RAT. Further, providing the information related to the relationship between the one or more parameters between the cells of the two or more RATs comprises providing, to the one or more wireless devices, per carrier information that indicates the relation between the cell IDs of the cells of the first RAT that operate on the carrier of the first RAT and the cell IDs of respective cells of the second RAT that operate within the bandwidth of the carrier of the first RAT.

[0033] In some embodiments, the per carrier information comprises a per carrier indicator that indicates whether the cells of the first RAT that operate on the carrier of the first RAT and the respective cells of the second RAT that operate within a bandwidth of the carrier of the first RAT have the same cell ID.

[0034] In some embodiments, the per carrier information comprises a per carrier indicator that indicates, for each of one or more sets of cells each comprising a first cell of the first RAT that operates on the carrier of the first RAT and a respective second cell of the second RAT that operates within a bandwidth of the carrier of the first RAT, whether the first cell and the respective second cell have the same cell ID. Further, in some embodiments, the per carrier indicator is an indication that indicates whether cells of the first RAT that operate on the carrier of the first RAT and respective cells of the second RAT that operate in- band or within a guard band of the carrier of the first RAT have the same cell ID. In some other embodiments, the per carrier indicator is an indication that indicates whether cells of the first RAT that operate on the carrier of the first RAT and respective cells of the second RAT that operate in-band, within a guard band, or in-band or within a guard band of the carrier of the first RAT have the same cell ID.

[0035] In some embodiments, the per carrier information comprises a per carrier indicator that indicates an offset between cells IDs of cells of the first RAT that operate on the carrier of the first RAT and respective cells of the second RAT that operate within the bandwidth of the carrier of the first RAT.

[0036] In some embodiments, the per carrier information on the cell ID relation of the two or more RATs comprises a per carrier indicator that indicates, for each of one or more sets of cells each comprising a first cell of the first RAT that operate on the carrier of the first RAT and a respective second cell of the second RAT that operates within a bandwidth of the carrier of the first RAT, an offset between a cell IDs of first cell and the respective second cell.

[0037] In some embodiments, the method further comprises receiving measurement results from the wireless device.

[0038] In some embodiments, the method further comprises determining whether the wireless device is capable of receiving signals of multiple RATs.

[0039] In some embodiments, providing the information related to the relationship between the one or more parameters between the cells of the two or more RATs comprises signaling, to the one or more wireless devices, first information related to a relation between a CE level of cells of the two or more RATs, and signaling, to the one or more wireless devices, second information related to a relation between SFNs of cells of the two or more RATs.

[0040] Embodiments of a network node are also disclosed. In some embodiments, a network node for a wireless communication network is adapted to perform any one of the aforementioned embodiments of a method of operation of a network node.

[0041] In some embodiments, a network node for a wireless communication network comprises at least one processor and memory storing instructions executable by the at least one processor whereby the network node is operable to provide, to one or more wireless devices, information related to a relationship between one or more parameters between cells of two or more RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT. Brief Description of the Drawings

[0042] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0043] Figure 1 illustrates one example of a wireless communication network in which embodiments of the present disclosure may be implemented;

[0044] Figure 2 is a flow chart that illustrates the operation of a wireless device according to some embodiments of the present disclosure;

[0045] Figure 3 is a flow chart that illustrates details of one of the steps of Figure 2 according to some embodiments of the present disclosure;

[0046] Figure 4 is a flow chart that illustrates details of one of the steps of Figure 2 according to some other embodiments of the present disclosure;

[0047] Figure 5 illustrates an example of how synchronization signals of a first and second Radio Access Technology (RAT) can be combined according to some embodiments of the present disclosure;

[0048] Figure 6 is a flow chart that illustrates the operation of a network node according to some embodiments of the present disclosure; [0049] Figure 7 is a flow chart that illustrates the operation of a wireless device according to some embodiments of the present disclosure;

[0050] Figure 8 is a flow chart that illustrates details of one of the steps of Figure 7 according to some embodiments of the present disclosure;

[0051] Figure 9 is a flow chart that illustrates details of one of the steps of Figure 7 according to some other embodiments of the present disclosure;

[0052] Figure 10 is a flow chart that illustrates the operation of a network node according to some embodiments of the present disclosure;

[0053] Figures 1 1 and 12 illustrate example embodiments of a wireless device; and

[0054] Figures 13 through 15 illustrate example embodiments of a network node.

Detailed Description

[0055] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0056] In some embodiments a more general term "network node" is used and it can correspond to any type of radio network node or any network node which communicates with a User Equipment device (UE) and/or with another network node. Examples of network nodes are a Node B, an enhanced or evolved Node B (eNB), a New Radio (NR) base station (gNB), a Master eNB (MeNB), a

Secondary eNB (SeNB), a network node belonging to a Master Cell Group (MCG) or a Secondary Cell Group (SCG), a base station, a Multi-Standard Radio (MSR) radio node such as a MSR base station, a network controller, a Radio Network Controller (RNC), a Base Station Controller (BSC), a relay, a donor node controlling relay, a Base Transceiver Station (BTS), an Access Point (AP), transmission points, transmission nodes, a Remote Radio Unit (RRU), a Remote Radio Head (RRH), nodes in a Distributed Antenna System (DAS), a core network node (e.g., a Mobile Switching Center (MSC), a Mobility Management Entity (MME), etc.), Operation and Management (O&M), an Operations Support System (OSS), a Self-Organizing Network (SON), a positioning node (e.g., an Evolved Serving Mobile Location Center (E-SMLC)), Minimization of Drive Tests (MDT), test equipment (physical node or software), etc.

[0057] In some embodiments the non-limiting term UE or wireless device is used and it refers to any type of wireless device communicating with a network node and/or with another UE in a cellular or mobile communication system.

Examples of a UE are a target device, a Device-to-Device (D2D) UE, a machine type UE or a UE capable of Machine-to-Machine (M2M) communication, a Personal Digital Assistant (PDA), an iPad, a tablet, mobile terminals, a smart phone, Laptop Embedded Equipment (LEE), Laptop Mounted Equipment (LME), Universal Serial Bus (USB) dongles, a Proximity Service (ProSe) UE, a Vehicle- to-Vehicle (V2V) UE, a Vehicle-to-X (V2X) UE, etc.

[0058] The term "radio measurement" (also known as measurements) used herein may refer to any measurement performed on radio signals. Examples of radio signals are Discovery Reference Signals (DRSs). Examples of DRSs are Positioning Reference Signal (PRS), Cell Specific Reference Signal (CRS),

Channel State Information Reference Signal (CSI-RS), Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), etc. In another example, DRSs can be any periodic signal with a configurable or predefined periodicity or signals based on a time-domain pattern. In another more narrow and specific example, DRS signals are as specified in Third Generation

Partnership Project (3GPP) Technical Specification (TS) 36.21 1 . Radio measurements can be absolute or relative. Radio measurements can be, e.g., intra-frequency, inter-frequency, Carrier Aggregation (CA), etc. Radio

measurements can be unidirectional (e.g., downlink or uplink) or bidirectional (e.g., Round Trip Time (RTT), Rx-Tx, etc.). Some examples of radio

measurements include: timing measurements (e.g., Time of Arrival (TOA), Timing Advance (TA), RTT, Reference Signal Time Difference (RSTD), System Frame Number (SFN) and Subframe Timing Difference (SSTD), Rx-Tx, propagation delay, etc.), angle 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 Indication (RSSI), noise power, Channel Quality Indication (CQI), Channel State Information (CSI), Precoding Matrix Indicator (PMI), etc.), cell detection or cell identification (also known as cell search), beam detection or beam identification, Radio Link Monitoring (RLM), system information reading, etc.

[0059] Performing a measurement on a carrier may imply performing measurements on signals of one or more cells operating on that carrier or performing measurements on signals of the carrier (also known as carrier specific measurement, e.g., RSSI). Examples of cell specific measurements are signal strength, signal quality, etc.

[0060] The term measurement performance used herein may refer to any criteria or metric which characterizes the performance of the measurement performed by a radio node, e.g., UE. The term measurement performance is also called measurement requirement, measurement performance requirements, etc. The radio node has to meet one or more measurement performance criteria related to the performed measurement. 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 with regard to a reference value (e.g., ideal

measurement result), etc. Examples of measurement time are measurement period, cell identification period, evaluation period, etc.

[0061] The coverage level of the UE may be defined with respect to any cell, e.g. serving cell, non-serving cell, neighbor cell, etc. The coverage level is also interchangeably called the Coverage Enhancement (CE) level. For example, the CE level with regard to a cell can be expressed in terms of signal level received at the UE from that cell. Alternatively, the CE level of the UE with regard to a cell can be expressed in terms of signal level received at the cell from the UE. As an example, received signal level can be expressed in terms of received signal quality and/or received signal strength at the UE with regard to the cell. More specifically, the coverage level may be expressed in terms of:

- received signal quality and/or received signal strength at the UE with regard to a cell; and/or

- received signal quality and/or received signal strength at the cell with regard to the UE.

[0062] Examples of signal quality are SNR, SINR, CQI, RSRQ, Narrowband RSRQ (NRSRQ), CRS Es/lot, Shared Channel (SCH) Es/lot, etc. Examples of signal strength are path loss, path gain, RSRP, Narrowband RSRP (NRSRP), SCH_RP, etc. The notation Es/lot is defined as ratio of:

· Es, which is the received energy per Resource Element (RE) (power normalized to the subcarrier spacing) during the useful part of the symbol, i.e., excluding the Cyclic Prefix (CP), at the UE antenna connector, to

• lot, which is the received power spectral density of the total noise and interference for a certain RE (power integrated over the RE and normalized to the subcarrier spacing) as measured at the UE antenna connector.

[0063] The CE level is also expressed in terms of two or more discrete levels or values, e.g. CE level 1 , CE level 2, CE level 3, etc. Consider an example of two coverage levels defined with regard to signal quality (e.g., SNR) at the UE comprising:

- CE level 1 (CE1 ) comprising SNR > -6 decibels (dB) at the UE with regard to a cell; and

- CE level 2 (CE2) comprising -15 dB < SNR < -6 dB at the UE with

regard to a cell. [0064] In the above example CE1 may also be interchangeably called normal coverage level, baseline coverage level, reference coverage level, legacy coverage level, etc. On the other hand, CE2 may be termed enhanced coverage or extended coverage level. A cell with enhanced or extended coverage level is considered to have a better or higher coverage level compared to a cell with a normal or baseline CE level. In the above example, a cell with CE2 is considered to have a better or higher coverage level compared to a cell with CE1 .

[0065] In another example, two different coverage levels (e.g., normal coverage and enhanced coverage) may be defined in terms of signal quality levels as follows:

- The requirements for normal coverage or Coverage Enhanced Mode A (CEModeA) are applicable for the UE category M1 with regard to a cell provided that radio conditions of the UE with respect to that cell are defined as follows: SCH Es/lot > -6 dB and CRS Es/lot > -6. - The requirements for enhanced coverage or Coverage Enhanced

Mode B (CEModeB) are applicable for the UE category M1 with regard to a cell provided that radio conditions of the UE with respect to that cell are defined as follows: SCH Es/lot > -15 dB and CRS Es/lot > -15.

[0066] In the above examples Es/lot is the ratio of received power per subcarrier to the total interference including noise per subcarrier.

[0067] The embodiments described herein may apply to any Radio Resource Control (RRC) state, e.g., RRC_CONNECTED or RRCJDLE.

[0068] A generic term network node is used in some embodiments. The network node can be a base station, an AP, a Node B, an eNB, a gNB, etc. A generic term wireless device is used in some embodiments. The wireless device can be any type of UE such as a D2D UE, a Machine Type Communication (MTC) UE, an enhanced MTC (eMTC) UE, a M2M UE, etc. The MTC or M2M UE may also be interchangeably called a narrowband or narrow bandwidth (BW) UE, a category 0 UE, a category M UE, a low cost and/or low complexity UE, etc. Yet another generic term, radio node, may be used in some embodiments. The radio node may be a network node or a wireless device. [0069] In some embodiments the term operating BW is used. Over the operating BW the network node transmits to and/or receives a signal from one or more UEs in a cell. The operating BW is interchangeably called channel BW, system BW, transmission BW, cell BW, cell transmission BW, carrier BW, etc. The operating BW may be expressed in different units. Examples of units are kilohertz (kHz), megahertz (MHz), number of resource blocks, number of REs, number of subcarriers, number of physical channels, number of frequency resource units, etc. The frequency channel or carrier frequency over which a Radio Access Technology (RAT) operates is enumerated or addressed by a channel number also known as Absolute Radio Frequency Channel Number (ARFCN), e.g. Evolved Universal Terrestrial Radio Access (E-UTRA) ARFCN (EARFCN) in Long Term Evolution (LTE), etc.

[0070] In some embodiments of the present disclosure the network node operates a cell using the first RAT over an operating BW (BW1 ) and transmits to and/or receives signals from one or more UEs (i.e., UE1 ) using the first RAT in a first cell (celH ). An example of the first RAT (RATI ) is LTE. Examples of operating BW (BW1 ) are 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz, etc. The network node also operates a cell using the second RAT (RAT2) over an operating BW (BW2) in cell2 wherein:

- BW2 is smaller than BW1 , i.e. BW2 < BW1 ; and

- BW2 operates within BW1 .

[0071] Examples of BW2 are 200 kHz, 180 kHz, one resource block, X number of subcarriers (e.g., X = 12 or 48 subcarriers), etc. The network node may also operate a second RAT using a plurality of channels of RAT2, e.g. two or more channels each of 200 kHz.

[0072] The operation of the second RAT within the BW of the first RAT is also called in-band operation, in-BW operation, etc. For consistency hereinafter the term in-band operation of the second RAT or simply in-band operation is used, which in turn herein implies that the second RAT operates within the part of the first RAT's BW (i.e., within BW1 ). [0073] The embodiments are also applicable for operation of the second RAT within the guard band of the carrier BW of the first RAT also known as guard band operation, guard BW operation, etc. The difference between in-band and guard band can be explained with the following example. Assume LTE (i.e., the first RAT) operates in 10 MHz of carrier frequency (i.e., BW1 = 10 MHz). The guard band of 10 MHz LTE carrier frequency is 1 MHz in total (i.e., 0.5 MHz on each side of the carrier). The Narrowband Internet of Things (NB-loT) operation (i.e., second RAT) in any one or more resource blocks within the central 9 MHz (i.e., 50 resource blocks) is considered to be in-band operation of the second RAT. However the NB-loT operation (i.e., second RAT) in any one or more resource blocks within the 1 MHz guard band (i.e., outside the central 9 MHz but within 10 MHz BW of the LTE) is considered to be guard band operation of the second RAT. The guard band depends on the carrier BW of the first RAT, e.g. it is 2 MHz in total for 20 MHz channel BW.

[0074] The network node may also transmit to and/or receive signals from one or more UEs using the second RAT in a second cell. The first and the second RATs are different. An example of the second RAT is an access technology operating using a BW narrower than the BW of the first RAT. For example BW1 and BW2 can be 10 MHz (i.e., 50 resource blocks) and 200 kHz (i.e., one resource block) respectively. A specific example of the second RAT is NB-loT.

[0075] By an E-UTRA MTC cell it is meant an E-UTRA cell that supports repetition of physical channels (e.g., PDSCH, Physical Uplink Shared Channel (PUSCH), etc.) for the purpose of coverage enhancement. By an MTC UE it is meant a UE capable of utilizing such repetitions for reception and/or transmission of physical channels.

[0076] In MTC operation under CE, the system acquisition delay can be very long. The system acquisition delay comprises the cell detection time which comprises the cell identification time and measurement time. In deep CE (e.g., at -15 dB Es/lot) the cell identification time can be up to 320 seconds, which makes it not very suitable for some use cases. [0077] Embodiments of the present disclosure relate to solutions that reduce cell identification delay for one RAT by utilizing known synchronization signals that belong to another RAT. In this regard, embodiments of a method of operation of a wireless device are disclosed. In some embodiments, a method of operation of a wireless device comprises the following steps, or actions, as illustrated in Figure 2 and discussed below in detail:

• Step 200 (Optional): The wireless device determines whether it is capable of dual MTC mode operation, or simply capable of receiving signals from at least two RATs (RATI and RAT2), when RAT2 operates within a BW of RATI .

• Step 202 (Optional): The wireless device determines that the serving or camping network node operates the first RAT (RATI ) and the second RAT (RAT2), where RAT2 operates within RATI BW.

• Step 204: The wireless device receives information from the serving or camping network node informing the wireless device about a relation between: a first set of cell Identifiers (IDs) of the cells of the first RAT (RATI ) operating on a first carrier (F1 ) and a second set of cell IDs of cells of the second RAT (RAT2) operating within the BW of RATI on F1.

• Step 206: The wireless device uses the received information for

adapting a measurement procedure for performing measurements on at least one cell of RATI and/or for performing measurements on at least one cell of RAT2, e.g. using signals of the cell on RAT2 for improving the measurement on the cell of RATI . Improving the measurement herein means acquiring the cell ID of the first RAT in shorter time compared to the time required to measure signals from the first RAT only.

[0078] Embodiments of a method of operation of a network node (e.g., a radio access node) are also disclosed. In some embodiments, a method of operation of a network node comprises the following steps, or actions, as illustrated in Figure 6 and discussed below in detail: • Step 600 (Optional): The network node determines whether a UE is capable of dual MTC mode operation, capable of operating at least a first RAT and a second RAT, or simply capable of receiving signals from multiple RATs (e.g., a first RAT and a second RAT).

· Step 602: The network node determines a relation between: a first set of cell IDs of the cells of the first RAT (RATI ) operating on a first carrier (F1 ) and a second set of cell IDs of cells of the second RAT (RAT2) operating within the BW of RATI on F1 .

• Step 604: The network node signals information (e.g., an indicator) informing the device about the determined relation in step 602.

• Step 606 (Optional): The network node receives the result of the

measurement from the UE performed by the UE based on the received relation and using it for one or more operational tasks (e.g., mobility, positioning, etc.).

[0079] Embodiments of the present disclosure improve system as well as wireless device performance by allowing a wireless device which is capable of receiving signals from a multiple RATs to improve the system acquisition time of one RAT using signals from another RAT. Further, in some embodiments, two RATs may be configured to support different levels of CE, and the embodiments disclosed herein enable the wireless device to use the signals from the strongest RAT to improve the performance of a weaker RAT.

[0080] Some other embodiments of the present disclosure relate to solutions that reduce cell identification delay for one RAT based on the relationship between System Information (SI) between cells of that RAT and cells of another RAT. In this regard, embodiments of a method of operation of a wireless device are disclosed. In some embodiments, a method of operation of a wireless device comprises the following steps, or actions, as illustrated in Figure 7 and discussed below in detail:

• Step 700 (Optional): The wireless device determines whether it is capable of receiving signals from multiple RATs when one RAT operates within a BW of the other RAT. For instance, the wireless device determines whether it is capable of dual MTC mode operation, or simply capable of receiving signals from at least two RATs (RATI and RAT2), when RAT2 operates within a BW of RATI .

• Step 702 (Optional): The wireless device determines whether a

serving or camping network node of the wireless device operates, or manages, the first RAT (RATI ) and the second RAT (RAT2), where RAT2 operates within the BW of RATI .

• Step 704: The wireless device obtains information related to a relation between a CE level of celH of RATI and a CE level of cell2 of RAT2. For example, the wireless device may obtain this information by receiving an indication of this information from a network node where the indication is mapped to this information (e.g., via a standard or some other predefined mapping), or the like. Other examples of how the wireless device may obtain this information are provided below. · Step 706: The wireless device obtains information about a relation between: a SFN of celH of RATI and a SFN of cell2 of RAT2 operating within the BW of celH . For example, the wireless device may obtain this information by receiving an indication of this information from a network node where the indication is mapped to this information (e.g., via standard or some other predefined mapping), or the like. Other examples of how the wireless device may obtain this information are provided below.

• Step 708: The wireless device uses the obtained information in

previous steps (steps 700 - 706) for acquiring SI of celH and/or for acquiring SI of cell2.

[0081] In some embodiments, a method of operation of a network node (e.g., a radio access node) comprises the following steps, or actions, as illustrated in Figure 10 and discussed below in detail:

• Step 1000 (Optional): The network node determines whether the

wireless device is capable of dual MTC mode operation, or simply capable of receiving signals from at least two RATs (RATI and RAT2), when RAT2 operates within a BW of RATI .

• Step 1002: The network node signals information to the wireless

device about a relation between a CE level of celH of RATI and a CE level of cell2 of RAT2.

• Step 1004: The network node signals information to the wireless

device about a relation between: a SFN of celH of RATI and a SFN of cell2 of RAT2 operating within the BW of celH .

[0082] The present disclosure improves system as well as wireless device performance by allowing a wireless device which is capable of receiving signals from a second RAT, in addition to the first RAT which it is configured on to the serving node, to improve the system acquisition time of the first RAT. In some embodiments, the two RATs may be configured to support different levels of CE, and embodiments of the present disclosure enable the wireless device to use the signals from the strongest RAT to improve the performance of the weaker RAT.

[0083] Figure 1 illustrates one example of a wireless communication network 100 (e.g., an LTE (e.g., LTE Advanced (LTE-A), LTE-Pro, or an enhanced version of LTE) or Fifth Generation (5G) NR network) in which embodiments of the present disclosure may be implemented. As illustrated, a number of wireless devices 102 (e.g., UEs) wirelessly transmit signals to and receive signals from radio access nodes 104 (e.g., eNBs or gNBs, which is a 5G NR base station), each serving one or more cells 106. The radio access nodes 104 are connected to a core network 108 that includes one or more core network nodes (not shown).

[0084] While not explicitly illustrated in Figure 1 , a radio access node 104 may serve multiple cells 106 on one or more carriers using one or more RATs (e.g., LTE and, e.g., NB-loT). For example, the radio access node 104 may serve a first set of cells 106 on a first carrier (F1 ) of a first RAT (RATI ) and also serve a second set of cells 106 of a second RAT (RAT2) that operate within the bandwidth of RATI on F1.

[0085] Figure 2 illustrates the operation of the wireless device 102 according to some embodiments of the present disclosure. With respect to all flow charts included herein, note that optional steps, if any, are indicated with dashed lines. Further, while the various actions are referred to as "steps," these steps may be performed in any desired order or even concurrently unless otherwise explicitly stated or required. The steps in the illustrated method of operation of the wireless device 102 are as follows:

• Step 200 (Optional): The wireless device 102 determines whether it is capable of receiving signals from multiple RATs. In some

embodiments, the wireless device 102 determines whether it is capable of a dual MTC mode operation or simply capable of receiving signals from at least two RATs (RATI and RAT2), when RAT2 operates within a BW of RATI .

• Step 202 (Optional): The wireless device 102 determines that the serving or camping network node (e.g., radio access node 104) of the wireless device 102 is managing multiple RATs. More specifically, the wireless device 102 determines that the serving or camping network node of the wireless device 102 operates a first RAT (RATI ) and a second RAT (RAT2), where RAT2 operates within the BW of RATI .

• Step 204: The wireless device 102 receives information from the

serving or camping network node (e.g., the radio access node 104) informing the wireless device 102 about a relation between cell IDs of two or more different RATs. For instance, the wireless device 102 receives information from the serving or camping network node informing the wireless device 102 about a relation between: a first set of cell IDs of the cells of the first RAT (RATI ) operating on a first carrier (F1 ) and a second set of cell IDs of cells of the second RAT

(RAT2) operating within the BW of RATI on F1 .

• Step 206: The wireless device 102 adapts a measurement

procedure(s) for performing measurements on at least one cell of at least one of the multiple RATs using the received information. For example, if there are two RATs (RATI and RAT2), the wireless device

102 uses the received information to adapt a measurement procedure for performing measurements on at least one cell of RATI and/or for performing measurements on at least one cell of RAT2 (e.g., using signals of the cell on RAT2 for improving the measurement on the cell of RATI ). Improving the measurement herein means acquiring the cell ID of the first RAT in a shorter time compared to the time required to measure signals from the first RAT only.

Each of these steps is described in more detail below.

[0086] Step 200: In step 200, the wireless device 102 determines whether it is capable of receiving signals from multiple RATs. In some particular

embodiments, the wireless device 102 determines whether it is capable of dual MTC mode of operation; i.e. whether the wireless device 102 is capable of operating two different RATs where RAT2 can operate within the BW of RATI (e.g., support both cat-M1 and cat-NB1 operations, where cat-NB1 operates within the BW of cat-M1 ). For example, the wireless device 102 supporting MTC operation as well as NB-loT operation may also be capable of supporting NB-loT operation within the BW of MTC (i.e., also known as in-band/guard band operation of NB-loT).

[0087] This information can be determined by the wireless device 102 by any of the following means:

· by retrieving it from the wireless device 102 memory (e.g., if hardcoded in the wireless device 102);

• by receiving a configuration from the operator based on, e.g., the type of subscription or fetched from the Subscriber Identity Module (SIM) card in the wireless device 102; and

· by receiving signals (e.g., reference signals, synchronization signals) from a second RAT which is different from the primary RAT. This can be based on information regarding whether said wireless device 102 operating in the cell on RATI is able to receive signals from a second cell on RAT2. If their BWs are overlapping, then it is likely that the wireless device 102 is able to receive the signals form the second

RAT. [0088] Step 202: In this step, the wireless device 102 determines whether the serving network node or the camping network node of the wireless device 102 is managing a second RAT (e.g., NB-loT) within the BW of the first RAT. In other words, assuming that the wireless device 102 is served or camped on a cell(s) of a first RAT, the wireless device 102 detects cells of the second RAT that are within the BW of the cell(s) of the first RAT.

[0089] If the network node is supporting a second RAT, the wireless device 102 may be able to identify the possible neighbor cells that belong to the second RAT. Inter-RAT neighbor cells are identified reading the synchronization signals. Thereafter, the wireless device 102 may acquire the Master Information Block (MIB) and Bandwidth Reduced System Information Block (SIB-BR) that contains the SI which is essential for the wireless device 102 to operate in that RAT. This is typically broadcasted in the MIB on the Physical Broadcasting Channel (PBCH) channel and the SI can be acquired from the corresponding data channel. This way, the wireless device 102 finds out about the presence of the second RAT within the same serving or camping network node.

[0090] For example, the wireless device 102 may compare the EARFCN, carrier frequency, system bandwidth location, or the center frequency location on the frequency domain to find out whether the second RAT is within the first RAT.

[0091] In some examples, the wireless device 102 may find out the presence of the second cell from a third node or a third party node, which is, e.g., a D2D capable node, a core network node, etc.

[0092] Step 204: In this step, the wireless device 102 receives information from the serving or camping network node (e.g., the radio access node 104) informing the wireless device 102 about a relation between the cell IDs of the cells of the different RATs. In particular, the wireless device 102 receives information from the serving or camping network node informing the wireless device 102 about a relation between:

• a first set of cell IDs of the cells belonging to the first RAT (RATI )

operating on a first carrier frequency (F1 ); and • a second set of cell IDs of cells belonging to the second RAT (RAT2) operating within the BW of RATI on F1.

[0093] As an example, NB-loT in-band and/or guard cells belong to RAT2 while MTC cells belong to RATI .

[0094] The information may be expressed in terms of an indicator about the relations between the cell IDs or it may contain more detailed information about the relations between the cell IDs.

[0095] The information is related to a plurality of cells (i.e., cells of RATI and RAT2, e.g., NB-loT and MTC cells) operating on the same carrier frequency (F1 ) of RATI within RATI BW (BW1 ). In one example, the information about the relation between cell IDs is related to all cells operating within the BW of the same carrier (i.e., F1 ). In another example, the information about the relation between cell IDs is related to neighbor cells operating within the BW of the same carrier. In yet another example, the information is related to a serving cell and a certain number of neighbor cells operating within the BW of the same carrier.

[0096] The information is per carrier information, e.g. separate indicators for serving carrier, for inter-frequency carrier, etc. The example of information about the relation is explained with several examples below:

1 . The information may comprise an indicator indicating to the wireless device 102 whether the cells of the first RAT and cells on the second

RAT operating on the same carrier (F1 ) within BW1 have the same cell ID or not. In one specific example, the first RAT is an LTE deployment and the second RAT is a NB-loT deployment. Similarly, the indicator can be used for indicating the per carrier information of the cells of any type of RAT. This is explained with a few examples below: i. One example of the information signaled to the wireless device 102 comprises a 1 -bit indicator as shown in Table 1 . In this example, the LTE cells and the NB-loT cells (of in-band and/or guard band deployment) have the same cell ID in the first signaled value (value #0). However, if the signaled value of the indicator is #1 then it means that the cell IDs of the LTE cells and the NB-loT cells are different,

ii. Another example where two bits are used to signal the per carrier information is shown in Table 2. In this example, the signaled values contain more detailed information. It is assumed that RAT2 is a NB-loT deployment, in which case it can be deployed as both in-band and guard band within the LTE cell. The 2-bit signaled values indicate a relation between cell IDs of the cells on same LTE carrier, i.e. between cells IDs of: LTE cell and in-band cell(s) within the LTE cell BW, LTE cell and guard band cell(s) within the LTE cell BW, and LTE cell and in-band/guard band cells within the LTE cell BW.

In another example, the information may comprise an offset (Ofs) between cell IDs of LTE cells and in-band/guard band cells within the LTE cell BW. This is expressed in Table 3. For example, the offset between any set of LTE and in-band/guard band cells within the LTE cell BW can be a fixed number (e.g., Ofs can be any value between 0 and 504).

Table 1 : Example of 1 -bit indicator containing per carrier information received from the network node

Table 2: Another example containing 2-bit indicator to signal the per carrier information LTE cell ID offset wrt

NB-loT (in-band/guard

Meaning Field description band) cell ID per

carrier

Ofs Within each set of LTE celH on carrier (F1 ) has cell ID#a

LTE cell and in- and NB-IOT (In-band/Guard-band) band/guard band cells within BW of LTE celM have cell NB-loT cells on the ID #a+Ofs; LTE cell2 on carrier (F1 ) same carrier of LTE has cell ID#b and NB-IOT (In- cell, there is fixed band/Guard-band) cells within BW of offset between their LTE cell2 has cell ID #b+Ofs; and so cell IDs. on.

Table 3: Example of information comprising of 'an offset between cell IDs per carrier' received from the network node

[0097] The column "Meaning" in each of Tables 1 -3 above provides examples of per carrier information on a cell ID relation of two or more RATs comprising a first RAT and a second RAT that operates within a BW of the first RAT.

[0098] The leftmost column in each of Tables 1 -3 above provide examples of information indicating per carrier information on a cell ID relation of two or more RATs comprising a first RAT and a second RAT that operates within a BW of the first RAT.

[0099] The above-mentioned information is signaled to the wireless device 102, e.g., in SI (e.g., MIB, SIB, etc.) and/or in a wireless device specific or dedicated message (e.g., in an RRC message via PDSCH). The information may additionally or alternatively be sent to the wireless device 102 during a specific procedure such as in cell change command (e.g., in a handover command). Examples of specific procedures are cell change, call setup, etc.

Specific examples of cell change procedures are handover, cell selection, cell reselection, RRC connection re-establishment, RRC connection release with redirection, etc.

[0100] Step 206: In this step, the wireless device 102 adapts a measurement procedure(s) for performing measurements on at least one cell of at least one of the multiple RATs based on the received information. For instance, the wireless device 102 performs identification of one or more cells on a carrier (F1 ) that belongs to the first RAT (RATI ) based on the received information about the cell ID relation between cells of RATI and RAT2 as described with respect to step 204.

[0101] The wireless device 102 may also perform identification of one or more cells belonging to RAT2 based on the received information about the cell ID relation between cells of RATI and RAT2 as described with respect to step 204. The embodiments are described for the case whereby the wireless device 102 enhances identification of one or more cells of RATI based on information about the cell ID relation between cells of RATI and RAT2. However, the

embodiments are also applicable for the converse situation, i.e. for the case whereby the wireless device 102 enhances identification of one or more cells of RAT2 based on information about the cell ID relation between cells of RATI and RAT2.

[0102] For example, as illustrated in Figure 3, in some embodiments, the wireless device 102 uses the synchronization signals (e.g., NB-loT SSS (NSSS), NB-loT PSS (NPSS)) of the second RAT to enhance the cell identification of the first RAT only when the received indicator shows that the cell IDs of the first RAT and the second RAT are the same for all cells on the same carrier (step 300, YES and step 302). Otherwise, if the received information shows that the cell IDs are different, then the wireless device 102 does not try to use the

synchronization signals of the second RAT to improve the cell identification of the first RAT (step 300, NO and step 304). This is because the sequences used to generate the synchronization signals in the RATI cell (e.g., the LTE cell) and RAT2 cell(s) (e.g., NB-loT cells within LTE BW) are different, thus the cell IDs are also different.

[0103] The impact of 1 -bit indicator defined in Table 1 on enhancement of the cell search procedure for identifying an LTE cell is expressed in Table 4.

[0104] The impact of the 2-bit indicator defined in Table 2 on enhancement of the cell search procedure for identifying an LTE cell is shown in Table 5. [0105] In case the wireless device 102 receives a cell offset value (i.e., according to Table 3), then the wireless device 102 uses NSSS/NPSS of in-band cell(s) and/or guard band cell(s) to acquire a cell ID of NB-loT cells. The wireless device 102 then determines the cell ID of the LTE cell based on the received offset (Ofs) and cell ID of the NB-loT cell based on a relation. The relation can be predefined or signaled to the UE by the network node. For example, the LTE cell ID can be derived by means of the following relation according to Table 3:

LTE cell ID = NB-loT cell ID + offset

One example of the details of step 206 that utilizes the cell offset value is shown in Figure 4. As illustrated, if the received information indicates that the cell IDs for all cells on the signaled carrier are the same (step 400, YES), the wireless device 102 performs cell identification of a cell(s) of one RAT (e.g., RATI ) by combining the signals from another RAT (e.g., RAT2), as described above (step 402). However, if the received information indicates that the cell IDs for all cells on the signaled carrier are not the same and a cell offset is not known (step 400, NO; step 404, NO), the wireless device 102 does not combine the signal from one RAT (e.g., RAT2) with those of another RAT (e.g., RATI ) for cell

identification, as described above (step 406). If the received information indicates that the cell IDs for all cells on the signaled carrier are not the same and a cell offset is known (step 400, NO; step 404, YES), the wireless device 102 performs cell identification of a cell(s) of one RAT (e.g., RAT2) using the signals from that RAT (step 408) and then applies the known cell offset to the obtained cell ID(s) of the RAT (e.g., RAT2) to thereby obtain the cell ID(s) of a cell(s) on another RAT (e.g., RATI ) (step 410).

[0106] In one example, the wireless device 102 may perform correlation between a received signal from an LTE cell and a CRS sequence corresponding to the determined LTE cell ID. This is done to verify that the LTE cell has been correctly identified. In another example, the wireless device 102 further identifies the LTE cell by correlating the received signals with the synchronization sequence of the LTE cell corresponding to the determined LTE cell ID. In this way the cell identification time is reduced and the LTE cell is also fully verified. Indicator Impact on cell search procedure

UE can use NB-loT cell(s)' NPSSS/NSSS also for identifying LTE cell

UE shall not use NB-loT cell(s)' NPSSS/NSSS also for identifying LTE cell

Table 4: Impact on LTE cell search based on receiving 1 -bit carrier specific indicator defined in Example 1 in Table 1

Table 5: Impact on LTE cell search based on receiving 2-bit carrier specific indicator defined in Example 2 in Table 2

[0107] Without the information (e.g., indicator) received in step 204, the wireless device 102 may have to autonomously try to decode and find out the cell IDs of the cells of the second RAT to determine whether they can be used for identification of the cells of the first RAT. The decoded cell IDs may or may not be same. If they are not the same, then the wireless device 102 may have wasted its resources to decode something that is not useful. The cost is both in terms of processing power and power consumption.

[0108] Instead, if the information of step 204 is signaled by the network node to the wireless device 102, then the wireless device 102 can do the cell search by using the synchronization signals of the second RAT (e.g., in-band and guard band cells) to improve the LTE cell search only when the received information indicates that the cell IDs are the same or, in some embodiments, when a cell offset is known. This will save both the processing power and power consumption in the UE as well as reduce the system acquisition time of the cells of the first RAT.

[0109] In one example, it is assumed that the received indicators point to the first value (value 0) in Table 1 , i.e. both LTE celH and NB-loT in-band cell within that cell have the same cell ID. The NB-loT cell can be either in-band or guard band. By utilizing this information, the wireless device 102 can use the synchronization signals transmitted for both the LTE cell and the NB-loT cell, i.e. there will be one additional Physical Resource Block (PRB) that contains the synchronization signal that can be used for the cell search of the LTE cell. In addition, if there are multiple NB-loT cells, (e.g., in-band and guard band) and they all contain the same cell IDs (i.e., the signaled parameter is 10 in Table 2), then there will be at least two additional PRBs containing the synchronization signals that can be used to improve the cell search of the cells of the first RAT. These additional PRBs of the second RAT can be significantly important especially when the cell search is done in deep CE. This can help in reducing the cell search time significantly.

[0110] Figure 5 illustrates an example of how the synchronization signals of a first RAT and signals of a second RAT can be combined to provide improved performance when the second RAT operates within the BW of the first RAT and the cell IDs of the cells of the first and second RATs are the same.

[0111 ] Figure 6 is a flow chart that illustrates the operation of a network node (e.g., a radio access node 104) according to some embodiments of the present disclosure. As illustrated, the process includes the following steps:

• Step 600 (Optional): The network node determines whether a UE is capable of dual MTC mode operation, capable of operating at least a first RAT and a second RAT, or simply capable of receiving signals from multiple RATs (e.g., a first RAT and a second RAT).

• Step 602: The network node determines a relation between: a first set of cell IDs of the cells of the first RAT (RATI ) operating on a first carrier (F1 ) and a second set of cell IDs of cells of the second RAT

(RAT2) operating within BW of RATI on F1 . • Step 604: The network node signals information (e.g., an indicator) informing the device about the determined relation in step 602.

• Step 606 (Optional): The network node receives the result of the

measurement from the UE performed by the UE based on the received relation and using it for one or more operational tasks (e.g., mobility, positioning, etc.).

These steps are descried in more detail below.

[0112] Step 600: In this step, the network node determines whether the wireless device 102 is capable of receiving signals from multiple RATs (e.g., capable of dual MTC mode operation, capable to operate at least a first RAT and a second RAT, or simply capable of receiving signals from multiple RATs (e.g., a first RAT and a second RAT)). The methods for determining are similar to those described with respect to step 200 above and, as such, are not repeated.

[0113] In addition, the network node may receive this capability information directly from the wireless device 102 or from a third node or third party node

(e.g., a core network node, a database, a server, etc. that contains the capability information of the wireless device 102, etc.).

[0114] Step 602: In this step, the network node determines the relation between a first set of cell IDs of the cells of the first RAT (RATI ) operating on a first carrier (F1 ) and a second set of cell IDs of cells of the second RAT (RAT2) operating within BW of RATI on F1.

[0115] For a network node serving cells of both RATs within the same BW on the same carrier, the cell ID information is typically known to the wireless device 102.

[0116] The description about the relation of the cell IDs described in step 204 above are also applicable here.

[0117] Step 604: In this step, the network node signals or transmits or configures the wireless device 102 with the determined relation between a first set of cell IDs of the cells of the first RAT (RATI ) operating on a first carrier (F1 ) and a second set of cell IDs of cells of the second RAT (RAT2) operating within the BW of RATI on F1. [0118] The information determined in step 602 can be, e.g., broadcasted to the wireless device 102 in system information (e.g., MIB, SIBs) by the network node, or signaled to the wireless device 102 using dedicated RRC signaling, etc.

[0119] Step 606: In this step, the network node receives the result of the measurement performed by the wireless device 102 based on the received relation and using it for one or more operational tasks.

[0120] The result of the measurements can be used by the network node for one or more operational tasks. Examples of operational tasks are mobility, positioning, measurement collection, obtaining measurement statistics, etc.

[0121] Figure 7 illustrates the operation of the wireless device 102 according to some embodiments of the present disclosure. With respect to all flow charts included herein, note that optional steps, if any, are indicated with dashed lines. Further, while the various actions are referred to as "steps," these steps may be performed in any desired order or even concurrently unless otherwise explicitly stated or required. The steps in the illustrated method of operation of the wireless device 102 are as follows:

Step 700 (Optional): The wireless device 102 determines whether it is capable of receiving signals from multiple RATs when one of the RATs operates within a BW of another one of the RATs. In some embodiments, the wireless device 102 determines whether it is capable of a dual MTC mode operation or simply capable of receiving signals from at least two RATs (RATI and RAT2), when RAT2 operates within a BW of RATI .

Step 702 (Optional): The wireless device 102 determines that the serving or camping network node (e.g., radio access node 104) of the wireless device 102 is managing multiple RATs. More specifically, the wireless device 102 determines that the serving or camping network node of the wireless device 102 operates a first RAT (RATI ) and a second RAT (RAT2), where RAT2 operates within the BW of RATI .

Step 704: The wireless device 102 obtains information related to a relation between CE levels of cells of the multiple RATs (e.g., information related to a relation between a CE level of celM of RATI and a CE level of cell2 of RAT2). For example, the wireless device 102 may obtain this information by receiving an indication of this information from a network node where the indication is mapped to this information (e.g., via a standard or some other predefined mapping), or the like. Other examples of how the wireless device 102 may obtain this information are provided below.

• Step 706: The wireless device 102 obtains information about a relation between SFNs of cells of the multiple RATs (e.g., information about a relation between a SFN of celH of RATI and a SFN of cell2 of RAT2 operating within the BW of celH ). For example, the wireless device 102 may obtain this information by receiving an indication of this information from a network node where the indication is mapped to this information (e.g., via a standard or some other predefined mapping), or the like. Other examples of how the wireless device 102 may obtain this information are provided below.

• Step 708: The wireless device 102 uses the obtained information in previous steps (steps 700 through 706) for acquiring SI cells of multiple RATs (e.g., acquiring SI of celH of RATI and/or acquiring SI of cell2 of RAT2).

Details of each of these steps are provided below.

[0122] Step 700: In step 700, the wireless device 102 determines whether it is capable of receiving signals from multiple RATs. In some particular

embodiments, the wireless device 102 determines whether it is capable of dual MTC mode operation; i.e. whether the wireless device 102 is capable of operating two different RATs where RAT2 can operate within the BW of RATI (e.g., support both cat-M1 and cat-NB1 operations, where cat-NB1 operates within the BW of cat-M1 ). For example, the wireless device 102 supporting MTC operation as well as NB-loT operation may also be capable of supporting NB-loT operation within the BW of MTC (i.e., also known as in-band/guard band operation of NB-loT). [0123] This information can be determined by the wireless device 102 by any of the following means:

• by retrieving it from the wireless device 102 memory (e.g., if hardcoded in the wireless device 102);

· by receiving it from the operator configuration based on, e.g., the type of subscription or fetched from the SIM card in the wireless device 102; and

• by receiving signals (e.g., reference signals, synchronization signals) from a second RAT which is different from the primary RAT. This can be based on information whether said wireless device 102 operating in a cell on RATI is able to receive signals from a second cell on RAT2. If their BWs are overlapping, then it is likely that the wireless device 102 is able to receive the signals form the second RAT.

[0124] Step 702: In this step, the wireless device 102 determines whether the serving network node or the camping network node of the wireless device 102 is managing a second RAT (e.g., NB-loT) within the BW of the first RAT. In other words, assuming that the wireless device 102 is served or camped on a cell(s) of a first RAT, the wireless device 102 detects cells of the second RAT that are within the BW of the cell(s) of the first RAT.

[0125] If the network node is supporting a second RAT, the wireless device 102 may be able to identify the possible neighbor cells that belong to the second RAT. Inter-RAT neighbor cells are identified reading the synchronization signals. Thereafter, the wireless device 102 may acquire the MIB and SIB-BR that contains the SI which is essential for the wireless device 102 to operate in that RAT. This is typically broadcasted in the MIB on the PBCH channel and the SI can be acquired from the corresponding data channel. This way, the wireless device 102 finds out the about the presence of the second RAT within the same serving or camping network node.

[0126] For example, the wireless device 102 may compare the EARFCN, carrier frequency, system bandwidth location, or the center frequency location on the frequency domain to find out whether the second RAT is within the first RAT. [0127] In some examples, the wireless device 102 may find out the presence of the second cell from a third node or a third party node, which is, e.g., a D2D capable node, a core network node, etc.

[0128] Step 704: In this step, the wireless device 102 obtains information about the relation between CE levels of cells of different RATs. For example, the wireless device 102 obtains information about the relation between the CE level of celH of RATI and the CE level of cell2 of RAT2, where RAT2 operates within the BW of celH . The wireless device 102 may obtain the information based on one or more of the following principles:

· Predefined relation between CE levels of celH and cell2, e.g., the CE of cell2 is X dB compared to CE of celH . In another example, predefined relation between CE levels of celH and cell2 can also be based on cell IDs. For example, the CE of cell2 is larger than X1 dB compared to the CE of celH provided that their cell IDs are the same; otherwise, the CE of cell2 is not larger than X1 dB compared to the CE of celH . In another example, the CE of cell2 is larger than X2 dB compared to the CE of celH provided that their cell IDs are within a certain range (e.g., 0, 1 , 28); otherwise, the CE of cell2 is not larger than X1 dB compared to the CE of celH ;

· Historical information or statistics, e.g., previously obtained or

determined relation between their respective CE levels, etc.; and • Information received from a network node, e.g., from the serving

network node, neighboring network node, etc.

[0129] In one example related to signaled information, a network node (e.g., the radio access node 104 of the serving or camping network node) may signal a relation between the coverage levels of celH and cell2 to the wireless device 102. For example, the network node may transmit the difference between CE levels of celH and cell2. In one example, the difference can be expressed in signal level, e.g., Y dB, where Y can be the difference between the signal quality levels experienced at the wireless device 102. In another example, the relation can be expressed as the difference between IDs of their CE levels. The CE level IDs can be predefined, e.g., CEO, CE1 , CE2, CEn with ID # 0, ID #1 , ID # 2, ID # n, respectively.

[0130] In another example, the wireless device 102 receives information in the form of an indicator from the network node indicating the relation between the CE level of the cell (celH ) that belongs to a first RAT and the CE level of another cell (cell2) that belongs to a second RAT, where RAT2 operates within the BW of the cell. One specific example of first RAT and second RAT are LTE MTC

deployment and NB-loT in-band and/or NB-loT guard band deployment, respectively.

[0131] One example of the received indicator comprises of one bit of information. This is shown in terms of the relation between the CE level of the LTE cell and the CE level of the NB-loT cell(s) (in-band and/or guard band cells) in Table 6. The first value (signaled value = 0) is used to indicate whether the NB-loT cell has better coverage (i.e., higher CE level) than the LTE cell.

Similarly, the second value (signaled value = 1 ) is used to indicate that the coverage level of the NB-loT cell(s) is the same or less than the coverage level of the LTE cell.

Table 6: Example 1 -bit indicator showing the relation between the coverage level of an LTE cell and the coverage level of NB-loT (in-band and guard band) cell(s), where NB-loT cell(s) operate within BW of the LTE cell. [0132] Similarly, with more numbers of bits used for signaling, more detailed information can be communicated to the wireless device 102. Here, this is exemplified by using 2-bit indicator in Table 7 wherein the signaled value can be per NB-loT deployment type.

Table 7: Another example containing 2-bit indicator showing the relation between the coverage level of an LTE cell and the coverage level of NB-loT (in-band and guard band) cell(s) where NB-loT cell(s) operate within BW of the LTE cell. [0133] The column "Meaning" in each of Tables 6-7 above provides examples of information related to a relation between a CE level of cells of two or more RATs, the two or more RATs comprising a first RAT and a second RAT that operates within a BW of the first RAT.

[0134] The leftmost column in each of Tables 6-7 above provides examples of information indicating information related to a relation between a CE level of cells of two or more RATs, the two or more RATs comprising a first RAT and a second RAT that operates within a BW of the first RAT. [0135] In the examples above, a cell (e.g., cell2) is considered to have better coverage if the CE level of that cell towards said UE is better than the first cell (e.g., celH ), i.e. CE level of celH is < CE level of cell2. The CE level can be based on the PRACH attempt, or based on the reported mobility measurements (e.g., RSRP, RSRQ, RS-SINR), SINR, SNR, CSI, CQI, PMI, etc.

[0136] For example, CE level 0 is said to have better coverage than CE level 1 , 2, 3. Typically the CE levels are defined based on the target Minimum

Coupling Loss (MCL). For example, the CE levels can be determined based on the reported RSRP measurement value or target MCL as follows:

· CE level 0 for MCL >144 dB

• CE level 1 for 144 < MCL < 154

• CE level 2 for 154 < MCL < 164

• CE level 3 for MCL < 164

[0137] The different coverage levels and how they are determined are described above.

[0138] In the above examples, celH and/or cell2 can be serving cell of the wireless device 102 or celH and/or cell2 can be the neighbor cell of the wireless device 102. For example, celH can be a target LTE cell (also known as neighbor cell) used for performing a cell change (e.g., handover, cell reselection, etc.).

[0139] The information related to the relation between CE levels of celH and cell2 as described above can be signaled to the wireless device 102 in a SI (e.g., MIB, SIB, SIB-BR, etc.) and/or in a UE specific or dedicated message (e.g., in RRC message via PDSCH). The information can be received by the wireless device 102 from the serving network node (e.g., by receiving a handover command) or from a neighboring network node (e.g., by reading its SI).

[0140] The above information may also be sent to the wireless device 102 during a specific procedure or scenarios or operations such as in cell change command (e.g., in a handover command sent by the network node). Examples of such procedures or operations are cell change, call setup, etc. Specific examples of cell change procedures or operations are handover, cell selection, cell reselection, RRC connection re-establishment, RRC connection release with redirection, etc.

[0141] Step 706: In this step, the wireless device 102 receives information related to a relation between SFNs of cells of different RATs. For example, the wireless device 102 receives information related to a relation between a SFN (SFN1 ) of a first cell (celM ) of the first RAT and a SFN (SFN2) of a second RAT, where cell2 operates within the bandwidth of celH . Similar to the examples above, examples of a first RAT is LTE cell and a second RAT is NB-loT in-band and/or guard band cell(s), where NB-loT in-band and/or guard band cell(s) are deployed within the BW of the LTE cell, i.e. the second RAT is within the BW of first RAT.

[0142] Several examples of the received information about the relation between SFNs of celH and cell2 are provided below.

[0143] The example in Table 8 contains a 1 -bit indicator comprising two values which indicate whether the SFN (SFN1 ) of celH on the first RAT and the

SFN (SFN2) of cell2 on the second RAT are the same or different.

[0144] The example in Table 9 contains a 2-bit indicator comprising four values which indicate whether the SFN (SFN1 ) of celH on the first RAT and the

SFN (SFN2) of cell2 on the second RAT are the same or different. The 2-bit indicator allows the wireless device 102 to explicitly determine the relation between SFNs of the LTE cell and specific type(s) of NB-loT cell (i.e., in-band and/or guard band cells).

Signaled

Meaning Field description

parameter

0 SFN of celH of RATI LTE celH on carrier (F1 ) and NB-IOT (In- is the same as SFN of band/Guard-band) cells (cell2) within BW of LTE eel 12 of RAT2 celH have the same SFN.

1 SFN of celH of RATI LTE celH on carrier (F1 ) and NB-IOT (In- is not the same as band/Guard-band) cells (cell2) within BW of LTE SFN of cell2 of RAT2 celH don't have the same SFN.

Table 8: Example of a 1 bit ind icator used to signal the relation between the SFNs of cells of the two RAT s, where RAT2 operates within BW of RATI

Signaled

Meaning Field description

parameter

00 SFN of celH of RATI LTE celM on carrier (F1 ) and NB-IOT in-band is the same as SFN of cells (cell2) within BW of LTE celH have the same in-band cell2 of RAT2 SFN.

01 SFN of celH of RATI LTE celH on carrier (F1 ) and NB-IOT guard-band is the same as SFN of cells (cell2) within BW of LTE celM have the same guard band cell2 of SFN.

RAT2

10 SFN of celH of RATI LTE celM on carrier (F1 ) and NB-IOT in- is the same as SFN of band/guard-band cells (cell2) within BW of LTE in-band/guard band celM have the same SFN.

cell2 of RAT2

1 1 SFN of celH of RATI LTE celM on carrier (F1 ) and any of NB-IOT in- is not the same as band/guard-band cells (cell2) within BW of LTE SFN of any cell2 of celM do not have the same SFN.

RAT2

Table 9: Example of 2-bit indicator used to signal the relation between the SFNs of cells of the two RATs, where RAT2 operates within BW of RATI

[0145] The column "Meaning" in each of Tables 8-9 above provides examples of information related to a relation between SFNs of cells of two or more RATs, the two or more RATs comprising a first RAT and a second RAT that operates within a BW of the first RAT.

[0146] The leftmost column in each of Tables 6-8 above provides examples of information indicating the two or more RATs comprising a first RAT and a second RAT that operates within a BW of the first RAT. [0147] In some examples, the received information may comprise the SFN values itself. For example, instead of indicating whether or not the SFN values are the same the actual SFN values are signaled to the wireless device 102.

[0148] In yet another example, the received SFN related information may comprise an offset indicating the relation between the SFN of the cell of the first and the second RAT. The offset can be a fixed value (e.g., Sfn_ofs) as shown in Table 10. The possible values of Sfn_ofn can be predefined. For example, Sfn_ofs can be any value from 0 to 1024. The network node signals the value of Sfn_Ofs is applicable for a particular LTE celM and NB-loT in-band/guard band cell2. In this case, if the wireless device 102 knows the SFN2 of cell2 then it will be able to determine (or derive) the SFN1 of celH using the predefined relation relating the two SFNs by the offset. An example of the relation is: SFN2 = f (SFN1 , sfn_Ofs). Another specific example of the relation is: SFN2 = SFN1 + sfn_Ofs. Alternatively, if the UE knows the SFN of celH then it will be able to determine the SFN of cell2 using a predefined relation relating the two SFNs by the offset.

Table 10: Another example of an indicator comprising an offset used to signal the

SFN relation between the cells of the two RATs

[0149] The information related to the relation between SFNs of celH and cell2 as described above can be signaled to the wireless device 102 in a SI (e.g., MIB, SIB, SIB-BR, etc.) and/or in a wireless device 102 specific or dedicated message (e.g., in RRC message via PDSCH). The information can be received by the wireless device 102 from the serving network node (e.g., by receiving a handover command) or from a neighboring network node (e.g., by reading its SI).

[0150] The above information may also be sent to the wireless device 102 during a specific procedure or scenarios or operations such as in cell change command (e.g., in a handover command sent by the network node). Examples of such procedures or operations are cell change, call setup, etc. Specific examples of cell change procedures or operations are handover, cell selection, cell reselection, RRC connection re-establishment, RRC connection release with redirection, etc.

[0151] Step 708: In this step, the wireless device 102 acquires SI of cell(s) based on the information obtained in steps 700 through 706. For example, based on the obtained information related to coverage levels and the SFNs as described in previous steps (step 704 and step 706), the wireless device 102 decides whether to acquire SI of celH of RATI according to a first SI acquisition procedure (P1 ) or according to a second SI acquisition procedure (P2).

[0152] An example of SI is MIB transmitting via PBCH (or Narrowband PBCH (NPBCH), etc.), SIB1 , SIB-BR, etc. The wireless device 102 may also acquire specific contents of the SI. Examples of specific contents are SFN transmitted in MIB, Cell Global ID (CGI) transmitted in SIB, etc.

[0153] According to procedure P1 , the wireless device 102 first acquires the SI of cell2 (SI2) and then uses the acquired SI2 for determining at least part of the SI of celH (SI1 ) of RATI . In procedure P1 the overall time to acquire SI1 is reduced compared to the case in which the wireless device 102 directly acquires SI1 by reading celH SI.

[0154] According to procedure P2, the wireless device 102 directly acquires the SI of celH (SI1 ) by reading SI1 , i.e. without acquiring SI2. In procedure P2 the overall time to acquire SI1 is reduced compared to the case in which the wireless device 102 first acquires SI2 by reading cell2 SI.

[0155] The wireless device 102 determines whether to acquire SI of celH based on the procedure P1 or procedure P2 according to the following rules, an example implantation of which is illustrated in Figure 8: If the received information (obtained in step 704 described above) relating to the coverage levels of the celH and cell2 indicates that cell2 has better coverage compared to that of celH (step 800, YES), then the wireless device 102 further uses SFN related information (obtained in step 706 described above) to decide whether to first acquire SI of cell2 (SI2) (step 802). If the information received/obtained/determined in step 706 indicates that the SFNs of celH and cell2 are the same and/or additional information about the SFN relation of the two cells of the two RATs is provided to the wireless device 102 (step 802, YES), then the wireless device 102 may first acquire SI of cell2 (e.g., may attempt to decode the MIB of cell2) (step 804). In this case the wireless device 102 applies procedure P1 for acquiring SI of celll That means the wireless device 102 uses the acquired SI2 for determining SI1 . For example, the wireless device 102 acquires SFN2 and assumes SFN1 = SFN2 or uses an offset to determine SFN1 from SFN2, i.e. SFN1 = SFN2 + Sfn_Ofs.

If the received information (obtained in step 704 described above) relating to the coverage levels of the celll and cell2 indicates that cell2 does not have better coverage compared to that of celll (step 800, NO), then the wireless device 102 directly acquires SI of celll (SI1 ), i.e. without reading SI of cell2 (step 806). Therefore in this case the wireless device 102 applies procedure P2 for acquiring SI of celll If the received information (obtained in step 704 described above) relating to the coverage levels of the celll and cell2 indicates that cell2 has better coverage compared to that of celll (step 800, YES), then the wireless device 102 further uses SFN related information (obtained in step 706 described above) to decide whether to first acquire SI of cell2 (SI2) (step 802). If the information received/obtained/determined in step 706 indicates that the SFNs of celll and cell2 are neither the same nor any additional information about the SFN relation of the two cells of the two RATs is provided to the wireless device 102 (step 802, NO), then the wireless device 102 may directly acquire SI of celH (SI1 ), i.e. without reading SI of cell2 (step 806). Therefore in this case the wireless device 102 also applies procedure P2 for acquiring SI of celll

[0156] According to another aspect of this embodiment, the wireless device 102 based on the obtained information related to coverage levels and the SFNs as described in previous steps (step 704 and step 706) decides whether to acquire SI of cell2 of RAT2 according to a third SI acquisition procedure (P3) or according to a fourth SI acquisition procedure (P4).

[0157] According to procedure P3, the wireless device 102 first acquires the SI of celH (SI1 ) and then uses the acquired SI1 for determining at least part of the SI of cell2 (SI2) of RAT2. In procedure P3, the overall time to acquire SI2 is reduced compared to the case in which the wireless device 102 directly acquires SI2 by reading cell2 SI.

[0158] According to procedure P4, the wireless device 102 directly acquires the SI of cell2 (SI2) by reading SI2, i.e. without acquiring SI1 . In procedure P4 the overall time to acquire SI2 is reduced compared to the case in which the wireless device 102 first acquires SI1 by reading celH SI.

[0159] The wireless device 102 determines whether to acquire SI of cell2 based on the procedure P3 or procedure P4 according to the following rules, an example implementation of which is illustrated in Figure 9:

- If the received information (obtained in step 704 in described above) relating to the coverage levels of the celH and cell2 indicates that celH has better coverage compared to that of cell2 (step 900, YES), then the wireless device 102 further uses SFN related information (obtained in step 706 described above) to decide whether to first acquire SI of celH (S 11 ) (step 902). If the information received/obtained/determined in step 706 indicates that the SFNs of celH and cell2 are the same and/or additional information about the SFN relation of the two cells of the two RATs is provided to the wireless device 102 (step 902, YES), then wireless device 102 may first acquire SI of celH (e.g., may attempt to decode the MIB of celH ). In this case the wireless device 102 applies procedure P3 for acquiring SI of cell2 (step 904). That means the wireless device 102 uses the acquired SI1 for determining SI2. For example, the wireless device 102 acquires SFN1 and assumes SFN2 = SFN1 or uses an offset to determine SFN2 from

SFN1 , i.e. SFN2 = SFN1 - Sfn_Ofs.

- If the received information (obtained in step 704 described above) relating to the coverage levels of the celH and cell2 indicates that celH does not have better coverage compared to that of cell2 (step 900, NO), then the wireless device 102 directly acquires SI of cell2 (SI2), i.e. without reading SI of celH (step 906). Therefore in this case, the wireless device 102 applies procedure P4 for acquiring SI of cell2.

- If the received information (obtained in step 704 described above) relating to the coverage levels of the celH and cell2 indicates that celH has better coverage compared to that of cell2 (step 900, YES), then the wireless device 102 further uses SFN related information (obtained in step 706 described above) to decide whether to first acquire SI of celH (S 11 ) (step 902). If the information received/obtained/determined in step 706 indicates that the SFNs of celH and cell2 are neither the same nor any additional information about the SFN relation of the two cells of the two RATs is provided to the wireless device 102 (step 902, NO), then the wireless device 102 may directly acquire SI of cell2 (SI2), i.e. without reading SI of celH (step 906). Therefore in this case, the wireless device 102 also applies procedure P4 for acquiring SI of celll

[0160] The wireless device 102 may experience or can be configured with different CE levels on cells of the different RATs. This makes reading of MIB depend on the coverage level as well. This means the reading of MIB will also depend on the said coverage level. In some scenarios, the second RAT (e.g., NB-loT anchor cell) can be power boosted compared to the first RAT which results in better coverage level for the wireless device 102 towards the second RAT. In such cases, it is highly likely that this wireless device 102 will

successfully read the MIB from the second RAT compared to the first RAT with moderate coverage level provided that the SFN relation is known.

[0161] In order to use the PBCH from a second RAT to improve the PBCH reading from a cell of a first RAT, at least some of the contents are in common or none of the contents are in common. When the contents are the same (which is known from the received information in step 706), the wireless device 102 can use the MIB from the second RAT to faster read the MIB of the first RAT. If none of the contents are common between the two RATs, then the UE shall not attempt to decode the MIB from the second RAT at all since it becomes irrelevant.

[0162] By applying any of the procedures P1 , P2, P3, or P4, the overall time to acquire the SI of the target cell is reduced. This in turn reduces the time of any procedure which requires the UE to acquire the SI (e.g., SFN) of the target cell. For example, one or more of these are reduced: cell reselection time, handover delay, cell selection time, RRC re-establishment delay, RRC

connection release with redirection delay, etc.

[0163] Figure 10 is a flow chart that illustrates the operation of a network node (e.g., a radio access node 104) according to some embodiments of the present disclosure. As illustrated, the process includes the following steps:

• Step 1000 (Optional): The network node determines whether the

wireless device 102 is capable of dual MTC mode operation, or simply capable of receiving signals from at least two RATs (RATI and RAT2), when RAT2 operates within a BW of RATI .

· Step 1002: The network node signals information to the wireless

device 102 about a relation between a CE level of celH of RATI and a CE level of cell2 of RAT2.

• Step 1004: The network node signals information to the wireless

device 102 about a relation between: a SFN of celM of RATI and a SFN of cell2 of RAT2 operating within the BW of celH . [0164] Step 1000: In this step, the network node determines whether the wireless device 102 is capable of dual MTC mode operation, capable to operate at least a first RAT and a second RAT, or simply capable of receiving signals from multiple RATs (e.g., a first RAT and a second RAT).

[0165] The methods for determining are similar to those described in step 700 above.

[0166] In addition, the network node may receive this capability information directly from the wireless device 102 or from a third node or third party node (e.g., a core network node, a database, a server, etc. that contains the capability information for the wireless device 102, etc.).

[0167] Step 1002: In this step, the network node signals or transmits or configures the wireless device 102 with the relation between a CE level of celH of RATI and a CE level of cell2 of RAT2, where RAT2 operates within BW of RAT

[0168] This information in step 1002 can be broadcasted to the wireless device 102 in SI (e.g., MIB, SIBs) by the network node, or signaled to the wireless device 102 using dedicated RRC signaling, etc.

[0169] The steps are similar to those described in step 704 above.

[0170] Step 1004: In this step, the network node signals or transmits or configures the wireless device 102 with the relation between a SFN off celH of RATI and a SFN of cell2 of RAT2 operating within the BW of celH .

[0171] This information in step 1004 can be broadcasted to the wireless device 102 in SI (e.g., MIB, SIBs) by the network node, or signaled to the wireless device 102 using dedicated RRC signaling, etc.

[0172] Figure 1 1 is a schematic block diagram of the wireless device 102 (e.g., UE) according to some embodiments of the present disclosure. As illustrated, the wireless device 102 includes circuitry 1 100 comprising one or more processors 1 102 (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Digital Signal Processors (DSPs), and/or the like) and memory 1 104. The wireless device 102 also includes one or more transceivers 1 106 each including one or more transmitters 1 108 and one or more receivers 1 1 10 coupled to one or more antennas 1 1 12. In some embodiments, the functionality of the wireless device 102 described herein may be implemented in hardware (e.g., via hardware within the circuitry 1 100 and/or within the processor(s) 1 102) or be implemented in a combination of hardware and software (e.g., fully or partially implemented in software that is, e.g., stored in the memory 1 104 and executed by the processor(s) 1 102).

[0173] In some embodiments, a computer program including instructions which, when executed by the at least one processor 1 102, causes the at least one processor 1 102 to carry out at least some of the functionality of the wireless device 102 according to any of the embodiments described herein is provided. In some embodiments, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0174] Figure 12 is a schematic block diagram of the wireless device 102 (e.g., UE) according to some other embodiments of the present disclosure. The wireless device 102 includes one or more modules 1200, each of which is implemented in software. The module(s) 1200 provide the functionality of the wireless device 102 described herein. For example, in some embodiments, the modules(s) 1200 may include a first determining module operable to perform the function of step 200 of Figure 2, a second determining function operable to perform the function of step 202 of Figure 2, a receiving module operable to perform the function of step 204 of Figure 2, and an adapting module operable to perform the function of step 206 of Figure 2. As another example, in some other embodiments, the modules(s) 1200 may include an optional first determining module operable to perform the function of step 700 of Figure 7, an optional second determining function operable to perform the function of step 702 of Figure 7, a first obtaining module operable to perform the function of step 704 of Figure 7, a second obtaining module operable to perform the function of step 706 of Figure 7, and an acquiring module operable to perform the function of step 708 of Figure 7.

[0175] Figure 13 is a schematic block diagram of a network node 1300 (e.g., a radio access node 104 such as, for example, an eNB or gNB or a core network node) according to some embodiments of the present disclosure. As illustrated, the network node 1300 includes a control system 1302 that includes circuitry comprising one or more processors 1304 (e.g., CPUs, ASICs, DSPs, FPGAs, and/or the like) and memory 1306. The control system 1302 also includes a network interface 1308. In embodiments in which the network node 1300 is a radio access node 104, the network node 1300 also includes one or more radio units 1310 that each include one or more transmitters 1312 and one or more receivers 1314 coupled to one or more antennas 1316. In some embodiments, the functionality of the network node 1300 (specifically the functionality of the radio access node 104) described above may be fully or partially implemented in software that is, e.g., stored in the memory 1306 and executed by the

processor(s) 1304.

[0176] Figure 14 is a schematic block diagram that illustrates a virtualized embodiment of the network node 1300 (e.g., the radio access node 104 or a core network node) according to some embodiments of the present disclosure. As used herein, a "virtualized" network node 1300 is a network node 1300 in which at least a portion of the functionality of the network node 1300 is implemented as a virtual component (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, the network node 1300 optionally includes the control system 1302, as described with respect to Figure 13. In addition, if the network node 1300 is the radio access node 104, the network node 1300 also includes the one or more radio units 1310, as described with respect to Figure 13. The control system 1302 (if present) is connected to one or more processing nodes 1400 coupled to or included as part of a network(s) 1402 via the network interface 1308. Alternatively, if the control system 1302 is not present, the one or more radio units 1310 (if present) are connected to the one or more processing nodes 1400 via a network interface(s). Alternatively, all of the functionality of the network node 1300 (e.g., all of the functionality of the radio access node 104 or the core network node 19) described herein may be implemented in the processing nodes 1400. Each processing node 1400 includes one or more processors 1404 (e.g., CPUs, ASICs, DSPs, FPGAs, and/or the like), memory 1406, and a network interface 1408.

[0177] In this example, functions 1410 of the network node 1300 (e.g., the functions of the radio access node 104 or the core network node 108) described herein are implemented at the one or more processing nodes 1400 or distributed across the control system 1302 (if present) and the one or more processing nodes 1400 in any desired manner. In some particular embodiments, some or all of the functions 1410 of the network node 1300 described herein are

implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 1400. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 1400 and the control system 1302 (if present) or alternatively the radio unit(s) 1310 (if present) is used in order to carry out at least some of the desired functions. Notably, in some

embodiments, the control system 1302 may not be included, in which case the radio unit(s) 1310 (if present) communicates directly with the processing node(s) 1400 via an appropriate network interface(s).

[0178] In some particular embodiments, higher layer functionality (e.g., layer 3 and up and possibly some of layer 2 of the protocol stack) of the network node 1300 may be implemented at the processing node(s) 1400 as virtual components (i.e., implemented "in the cloud") whereas lower layer functionality (e.g., layer 1 and possibly some of layer 2 of the protocol stack) may be implemented in the radio unit(s) 1310 and possibly the control system 1302.

[0179] In some embodiments, a computer program including instructions which, when executed by the at least one processor 1304, 1404, causes the at least one processor 1304, 1404 to carry out the functionality of the network node 1300 or a processing node 1400 according to any of the embodiments described herein is provided. In some embodiments, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as the memory 1406).

[0180] Figure 15 is a schematic block diagram of the network node 1300 (e.g., the radio access node 104 or a core network node) according to some other embodiments of the present disclosure. The network node 1300 includes one or more modules 1500, each of which is implemented in software. The module(s) 1500 provide the functionality of the network node 1300 described herein. In some embodiments, the module(s) 1500 comprise, for example, an optional first determining module operable to perform the function of step 600 of Figure 6, a second determining module operable to perform the function of step 602 of Figure 6, a transmitting module operable to perform the function of step 604 of Figure 6, and an optional receiving module operable to perform the function of step 606 of Figure 6. As another example, in some other embodiments, the module(s) 1500 comprise, for example, an optional determining module operable to perform the function of step 1000 of Figure 10, a first signaling module operable to perform the function of step 1002 of Figure 10, and a second signaling module operable to perform the function of step 1004 of Figure 10.

Example Embodiments

[0181] While not being limited thereto, some example embodiments of the present disclosure are provided below.

[0182] Embodiment 1 : A method of operation of a wireless device (102) in a wireless communication network (100), comprising: receiving (204) information indicating per carrier information on a cell ID relation of two or more RATs comprising a first RAT and a second RAT that operates within a bandwidth of the first RAT and, based on the received information, adapting (206) a measurement procedure for performing measurements on at least one cell of the first RAT based on the information and signals received on at least one cell of the second RAT and/or at least one cell of the second RAT based on the information and signals received on at least one cell of the first RAT.

[0183] Embodiment 2: The method of embodiment 1 wherein the per carrier information on the cell ID relation of the two or more RATs comprises, for a first carrier of the first RAT, information that indicates that cell IDs of the first RAT are the same as cell IDs of the second RAT that operate within the bandwidth of the first RAT (i.e., the bandwidth of the first carrier of the first RAT).

[0184] Embodiment 3: The method of embodiment 2 wherein adapting (206) the measurement procedure comprises performing (302) cell identification of: a cell on the first carrier of the first RAT using a combination of signals received from one or more cells of the first RAT operating on the first carrier and signals received from one or more cells of the second RAT that are operating in the bandwidth first RAT; and/or a cell of the second RAT using a combination of signals received from one or more cells of the first RAT operating on the first carrier and signals received from one or more cells of the second RAT that are operating in the bandwidth first RAT.

[0185] Embodiment 4: The method of embodiment 1 wherein the per carrier information on the cell ID relation of the two or more RATs comprises, for a first carrier of the first RAT, information that indicates a cell offset between cell IDs of the first RAT and cell IDs of the second RAT that operate within the bandwidth of the first RAT (i.e., the bandwidth of the first carrier of the first RAT).

[0186] Embodiment 5: The method of embodiment 4 wherein adapting (206) the measurement procedure comprises: performing (408) cell identification of one or more cells of the second RAT operating within the bandwidth of the first RAT; and applying (410) the cell offset to cell IDs identified for the one or more cells of the second RAT operating within the bandwidth of the first RAT to thereby obtain cell IDs of one or more cells of the first RAT that are operating on the first carrier.

[0187] Embodiment 6: The method of any one of embodiments 1 to 5 further comprising determining whether the wireless device (102) is capable of receiving signals of multiple RATs. [0188] Embodiment 7: The method of any one of embodiments 1 to 6 further comprising determining whether a serving or camping network node is managing multiple RATs.

[0189] Embodiment 8: A wireless device (102) for a wireless communication network (100), the wireless device (102) adapted to perform the method of any one of embodiments 1 to 7.

[0190] Embodiment 9: A wireless device (102) for a wireless communication network (100), comprising: at least one transceiver (1 106); and circuitry (1 100) associated with the at least one transceiver (1 106) operable to perform the method of any one of embodiments 1 to 7.

[0191] Embodiment 10: A wireless device (102) for a wireless communication network (100), comprising: one or more modules (1200) operable to perform the method of any one of embodiments 1 to 7.

[0192] Embodiment 1 1 : A computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of embodiments 1 to 7.

[0193] Embodiment 12: A carrier containing the computer program of embodiment 1 1 , wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

[0194] Embodiment 13: A method of operation of a network node (104, 1300) in a wireless communication network (100), comprising: determining (602) a relation between a first set of cell IDs of cells of a first RAT that operate on a first carrier of the first RAT and a second set of cell IDs of cells of a second RAT that operate within a bandwidth of the first RAT (i.e., within a bandwidth of the first carrier of the first RAT); and providing (604) information that indicates the relation between the first and second sets of cell IDs to a wireless device (102).

[0195] Embodiment 14: The method of embodiment 13 wherein the first set of cell IDs and the second set of cell IDs are the same, and the information indicates that the first set of cell IDs and the second set of cell IDs are the same.

[0196] Embodiment 15: The method of embodiment 13 wherein the first set of cell IDs are offset from the second set of cell IDs by a cell offset value, and per carrier information on the cell ID relation of the two or more RATs comprises, the information indicates the cell offset value.

[0197] Embodiment 16: The method of any one of embodiments 13 to 15 further comprising receiving (606) measurement results from the wireless device (102).

[0198] Embodiment 17: The method of any one of embodiments 13 to 16 further comprising determining (600) whether the wireless device (102) is capable of receiving signals of multiple RATs.

[0199] Embodiment 18: A network node (104, 1300) for a wireless

communication network (100), the network node (104, 1300) adapted to perform the method of any one of embodiments 13 to 17.

[0200] Embodiment 19: A network node (104, 1300) for a wireless

communication network (100), comprising: at least one processor (1304, 1404); and memory (1306, 60) storing instructions executable by the at least one processor (1304, 1404) whereby the network node (104, 1300) is operable to perform the method of any one of embodiments 13 to 17.

[0201] Embodiment 20: A network node (104, 1300) for a wireless

communication network (100), comprising: one or more modules (1500) operable to perform the method of any one of embodiments 13 to 17.

[0202] Embodiment 21 : A computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of embodiments 13 to 17.

[0203] Embodiment 22: A carrier containing the computer program of embodiment 21 , wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

[0204] Embodiment 23: A method of operation of a wireless device (102) in a wireless communication network (100), comprising: obtaining (704) first information related to a relation between a coverage enhancement level of cells of two or more RATs, the two or more RATs comprising a first RAT and a second RAT that operates within a bandwidth of the first RAT; obtaining (706) second information related to a relation between SFNs of cells of the two or more RATs; and acquiring (708) system information of one or more first cells of the first RAT and/or one or more cells of the second RAT that operate within a bandwidth of the one or more first cells of the first RAT based on the first information and the second information.

[0205] Embodiment 24: The method of embodiment 23 wherein acquiring (708) system information comprises acquiring (708) system information of one or more first cells of the first RAT and/or one or more cells of the second RAT that operate within a bandwidth of the one or more first cells of the first RAT using different procedures depending on the content of the first information and the second information.

[0206] Embodiment 25: The method of embodiment 23 wherein: determining (800, YES) that the first information indicates that a coverage enhancement level of a second cell of the second RAT is better than a coverage enhancement level of a first cell of the first RAT, where the second cell of the second RAT that operates within a bandwidth of the first cell of the first RAT; determining (802, YES) that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are the same and/or comprises additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT; and acquiring (708) system information comprises acquiring (804) system information of the second cell of the second RAT and using (804) the system information of the second cell of the second RAT to determine at least part of system information of the first cell of the first RAT.

[0207] Embodiment 26: The method of embodiment 23 wherein determining (800, YES) that the first information indicates that a coverage enhancement level of a second cell of the second RAT is better than a coverage enhancement level of a first cell of the first RAT, where the second cell of the second RAT that operates within a bandwidth of the first cell of the first RAT; determining (802, NO) that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are not the same and comprises no additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT; and acquiring (708) system information comprises directly acquiring (806) system information of the first cell of the first RAT.

[0208] Embodiment 27: The method of embodiment 23 wherein determining (800, NO) that the first information indicates that a coverage enhancement level of a second cell of the second RAT is not better than a coverage enhancement level of a first cell of the first RAT, where the second cell of the second RAT that operates within a bandwidth of the first cell of the first RAT; and acquiring (708) system information comprises directly acquiring (806) system information of the first cell of the first RAT.

[0209] Embodiment 28: The method of embodiment 23 wherein determining (900, YES) that the first information indicates that a coverage enhancement level of a first cell of the first RAT is better than a coverage enhancement level of a second cell of the second RAT that operates within a bandwidth of the first cell; determining (902, YES) that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are the same and/or comprises additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT; and acquiring (708) system information comprises acquiring (904) system information of the first cell of the first RAT and using (904) the system information of the first cell of the first RAT to determine at least part of system information of the second cell of the second RAT.

[0210] Embodiment 29: The method of embodiment 23 wherein determining (900, YES) that the first information indicates that a coverage enhancement level of a first cell of the first RAT is better than a coverage enhancement level of a second cell of the second RAT that operates within a bandwidth of the first cell; determining (902, NO) that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are not the same and comprises no additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT; and acquiring (708) system information comprises directly acquiring (906) system information of the second cell of the second RAT.

[0211] Embodiment 30: The method of embodiment 23 wherein determining (900, NO) that the first information indicates that a coverage enhancement level of a first cell of the first RAT is not better than a coverage enhancement level of a second cell of the second RAT that operates within a bandwidth of the first cell; and acquiring (708) system information comprises directly acquiring (906) system information of the second cell of the second RAT.

[0212] Embodiment 31 : A wireless device (102) for a wireless communication network (100), the wireless device (102) adapted to perform the method of any one of embodiments 23 to 30.

[0213] Embodiment 32: A wireless device (102) for a wireless communication network (100), comprising: at least one transceiver (1 106); and circuitry (1 100) associated with the at least one transceiver (1 106) operable to perform the method of any one of embodiments 23 to 30.

[0214] Embodiment 33: A wireless device (102) for a wireless communication network (100), comprising one or more modules (1200) operable to perform the method of any one of embodiments 23 to 30.

[0215] Embodiment 34: A computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of embodiments 23 to 30.

[0216] Embodiment 35: A carrier containing the computer program of embodiment 34, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

[0217] Embodiment 36: A method of operation of a network node (104, 1300) in a wireless communication network (100), comprising: signaling (1002), to a wireless device (102), first information related to a relation between a coverage enhancement level of cells of two or more RATs, the two or more RATs comprising a first RAT and a second RAT that operates within a bandwidth of the first RAT; and signaling (704), to the wireless devices (102), second information related to a relation between SFNs of cells of the two or more RATs. [0218] Embodiment 37: A network node (104, 1300) for a wireless

communication network (100), the network node (104, 1300) adapted to: signal, to a wireless device (102), first information related to a relation between a coverage enhancement level of cells of two or more RATs, the two or more RATs comprising a first RAT and a second RAT that operates within a bandwidth of the first RAT; and signal, to the wireless devices (102), second information related to a relation between SFNs of cells of the two or more RATs.

[0219] Embodiment 38: A network node (104, 1300) for a wireless

communication network (100), comprising: at least one processor (1304, 1404); and memory (1306, 1406) storing instructions executable by the at least one processor (1304, 1404) whereby the network node (104, 1300) is operable to signal, to a wireless device (102), first information related to a relation between a coverage enhancement level of cells of two or more RATs, the two or more RATs comprising a first RAT and a second RAT that operates within a bandwidth of the first RAT and signal, to the wireless devices (102), second information related to a relation between SFNs of cells of the two or more RATs.

[0220] Embodiment 39: A network node (104, 1300) for a wireless

communication network (100), comprising: a first signaling module (1500) operable to signal, to a wireless device (102), first information related to a relation between a coverage enhancement level of cells of two or more RATs, the two or more RATs comprising a first RAT and a second RAT that operates within a bandwidth of the first RAT; and a second signaling module (1500) operable to signal, to the wireless devices (102), second information related to a relation between SFNs of cells of the two or more RATs.

[0221] Embodiment 40: A computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to embodiment 36.

[0222] Embodiment 41 : A carrier containing the computer program of embodiment 40, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

[0223] The following acronyms are used throughout this disclosure. • 3GPP Third Generation Partnership Project

• 5G Fifth Generation

• AP Access Point

• ARFCN Absolute Radio Frequency Channel Number

• ASIC Application Specific Integrated Circuit

• BSC Base Station Controller

• BTS Base Transceiver Station

• BW Bandwidth

• CA Carrier Aggregation

• CE Coverage Enhancement

• CEModeA Coverage Enhanced Mode A

• CEModeB Coverage Enhanced Mode B

• CGI Cell Global Identifier

• CP Cyclic Prefix

• CPU Central Processing Unit

• CQI Channel Quality Indication

• CRS Cell Specific Reference Signal

• CSI Channel State Information

• CSI-RS Channel State Information Reference Signal

• D2D Device-to-Device

• DAS Distributed Antenna System

• dB Decibel

• DRS Discovery Reference Signal

• DSP Digital Signal Processor

• EARFCN Evolved Universal Terrestrial Radio Access Absolute

Radio Frequency Channel Number

• eMTC Enhanced Machine Type Communication

• eNB Enhanced or Evolved Node B

• E-SMLC Evolved Serving Mobile Location Center

• E-UTRA Evolved Universal Terrestrial Radio Access • FeMTC Further Enhancements for Machine Type Communication

• FPGA Field Programmable Gate Array

. gNB New Radio Base Station

• HD-FDD Half Duplex Frequency Division Duplexing

• ID Identity/Identifier

• kHz Kilohertz

• LEE Laptop Embedded Equipment

• LME Laptop Mounted Equipment

• LTE Long Term Evolution

• LTE -A Long Term Evolution Advanced

• M2M Machine-to-Machine

• MCG Master Cell Group

• MCL Minimum Coupling Loss

• MDT Minimization of Drive Tests

• MeNB Master Enhanced or Evolved Node B

• MHz Megahertz

• MIB Master Information Block

• MME Mobility Management Entity

• MPDSCH Massive Physical Downlink Shared Channel

• MSC Mobile Switching Center

• MSR Multi-Standard Radio

• MTC Machine Type Communication

• NB-loT Narrowband Internet of Things

• NPBCH Narrowband Physical Broadcasting Channel

• NPSS Narrowband Internet of Things Primary

Synchronization Signal

• NR New Radio

• NRSRP Narrowband Reference Signal Received Power

• NRSRQ Narrowband Reference Signal Received Quality NSSS Narrowband Internet of Things Secondary

Synchronization Signal

O&M Operation and Management

OSS Operations Support System

PBCH Physical Broadcasting Channel

PDA Personal Digital Assistant

PDSCH Physical Downlink Shared Channel

PMI Precoding Matrix Indicator

PRACH Physical Random Access Channel

PRB Physical Resource Block

ProSe Proximity Service

PRS Positioning Reference Signal

PSS Primary Synchronization Signal

PUSCH Physical Uplink Shared Channel

RAT Radio Access Technology

RE Resource Element

RLM Radio Link Monitoring

RNC Radio Network Controller

RRC Radio Resource Control

RRH Remote Radio Head

RRM Radio Resource Management

RRU Remote Radio Unit

RSRP Reference Signal Received Power

RSRQ Reference Signal Received Quality

RSSI Received Signal Strength Indication

RSTD Reference Signal Time Difference

RTT Round Trip Time

Rx Receiver

SCG Secondary Cell Group

SCH Shared Channel • SeNB Secondary Enhanced or Evolved Node B

• SFN System Frame Number

• SI System Information

• SIB System Information Block

· SIB-BR Bandwidth Reduced System Information Block

• SIM Subscriber Identity Module

• SINR Signal to Interference plus Noise Ratio

• SNR Signal to Noise Ratio

• SON Self-Organizing Network

· SSS Secondary Synchronization Signal

• SSTD System Frame Number and Subframe Timing

Difference

• TA Timing Advance

• TOA Time of Arrival

· TS Technical Specification

• UE User Equipment

• USB Universal Serial Bus

• V2X Vehicle-to-X

• V2V Vehicle-to-Vehicle

[0224] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Claims What is claimed is:

1 . A method of operation of a wireless device (102) in a wireless

communication network (100), comprising:

obtaining (204, 704, 706) information related to a relationship between one or more parameters between cells of two or more Radio Access

Technologies, RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT; and

performing (206, 708) one or more tasks based on the information.

2. The method of claim 1 wherein the information related to the relationship between the one or more parameters between the cells of the two or more RATs comprises information indicating per carrier information on a cell Identity, ID, relation of the two or more RATs.

3. The method of claim 2 wherein:

obtaining (204, 704, 706) the information related to the relationship between the one or more parameters between the cells of the two or more RATs comprises receiving (204) the information indicating the per carrier information on the cell ID relation of the two or more RATs; and

performing the one or more tasks based on the information comprises adapting (206) a measurement procedure for performing measurements on at least one cell of the first RAT and/or at least one cell of the second RAT based on the per carrier information on the cell ID relation of the two or more RATs.

4. The method of claim 3 wherein adapting (206) the measurement procedure comprises adapting (206) the measurement procedure for performing measurements on: at least one cell of the first RAT based on the information indicating the per carrier information on the cell ID relation of the two or more RATs and signals received on at least one cell of the second RAT; and/or

at least one cell of the second RAT based on the information indicating the per carrier information on the cell ID relation of the two or more RATs and signals received on at least one cell of the first RAT.

5. The method of claim 3 or 4 wherein the per carrier information on the cell ID relation of the two or more RATs comprises a per carrier indicator that indicates whether cells of the first RAT that are operating on a carrier of the first RAT and respective cells of the second RAT that are operating within a bandwidth of the carrier of the first RAT have the same cell ID.

6. The method of claim 3 or 4 wherein the per carrier information on the cell ID relation of the two or more RATs comprises a per carrier indicator that indicates, for each of one or more sets of cells each comprising a first cell of the first RAT that is operating on a carrier of the first RAT and a respective second cell of the second RAT that is operating within a bandwidth of the carrier of the first RAT, whether the first cell and the respective second cell have the same cell ID.

7. The method of claim 6 wherein the per carrier indicator is an indication that indicates whether cells of the first RAT that are operating on the carrier of the first RAT and respective cells of the second RAT that are operating in-band or within a guard band of the carrier of the first RAT have the same cell ID.

8. The method of claim 6 wherein the per carrier indicator is an indication that indicates whether cells of the first RAT that are operating on the carrier of the first RAT and respective cells of the second RAT that are operating in-band, within a guard band, or in-band or within a guard band, of the carrier of the first RAT have the same cell ID.

9. The method of claim 3 or 4 wherein the per carrier information on the cell ID relation of the two or more RATs comprises a per carrier indicator that indicates an offset between cell IDs of cells of the first RAT that are operating on a carrier of the first RAT and respective cells of the second RAT that are operating within the bandwidth of the carrier of the first RAT.

10. The method of claim 3 or 4 wherein the per carrier information on the cell ID relation of the two or more RATs comprises a per carrier indicator that indicates, for each of one or more sets of cells each comprising a first cell of the first RAT that is operating on a carrier of the first RAT and a respective second cell of the second RAT that is operating within a bandwidth of the carrier of the first RAT, an offset between a cell IDs of first cell and the respective second cell.

1 1 . The method of claim 3 or 4 wherein the per carrier information on the cell ID relation of the two or more RATs comprises information that indicates that cell IDs of cells of the first RAT that operate on a carrier of the first RAT are the same as cell IDs of the second RAT that operate within the bandwidth of the carrier of the first RAT.

12. The method of claim 1 1 wherein adapting (206) the measurement procedure comprises performing (302) cell identification of:

a cell on the carrier of the first RAT using a combination of signals received from one or more cells of the first RAT operating on the carrier of the first RAT and signals received from one or more cells of the second RAT that are operating in the bandwidth of the carrier of the first RAT; and/or

a cell of the second RAT using a combination of signals received from one or more cells of the first RAT operating on the carrier of the first RAT and signals received from one or more cells of the second RAT that are operating in the bandwidth of the carrier of the first RAT.

13. The method of claim 3 or 4 wherein the per carrier information on the cell ID relation of the two or more RATs comprises information that indicates a cell offset between cell IDs of cells operating on a carrier of the first RAT and cell IDs of cells of the second RAT that operate within the bandwidth of the carrier of the first RAT.

14. The method of claim 13 wherein adapting (206) the measurement procedure comprises:

performing (408) cell identification of one or more cells of the first RAT operating on the carrier of the first RAT; and

applying (410) the cell offset to cell IDs identified for the one or more cells of the first RAT operating on the carrier of the first RAT to thereby obtain cell IDs of one or more respective cells of the second RAT that are operating within the bandwidth of the carrier of the first RAT.

15. The method of claim 13 wherein adapting (206) the measurement procedure comprises:

performing (408) cell identification of one or more cells of the second RAT operating within the bandwidth of the carrier of the first RAT; and

applying (410) the cell offset to cell IDs identified for the one or more cells of the second RAT operating within the bandwidth of the carrier of the first RAT to thereby obtain cell IDs of one or more respective cells of the first RAT that are operating on the carrier of the first RAT.

16. The method of any one of claims 3 to 15 further comprising determining whether the wireless device (102) is capable of receiving signals of multiple RATs.

17. The method of any one of claims 3 to 16 further comprising determining whether a serving or camping network node is managing multiple RATs.

18. The method of claim 1 wherein:

• obtaining (204, 704, 706) the information related to the relationship

between one or more parameters between cells of the two or more RATs comprises:

o obtaining (704) first information related to a relation between a

coverage enhancement level of the cells of the two or more RATs; and

o obtaining (706) second information related to a relation between System Frame Numbers, SFNs, of cells of the two or more RATs; and · performing (206, 708) the one or more tasks based on the information comprises acquiring (708) system information of:

o one or more first cells of the first RAT; and/or

o one or more cells of the second RAT that operate within a bandwidth of the one or more first cells of the first RAT based on the first information and the second information.

19. The method of claim 18 wherein acquiring (708) the system information comprises acquiring (708) the system information of the one or more first cells of the first RAT and/or the one or more cells of the second RAT that operate within the bandwidth of the one or more first cells of the first RAT using different procedures depending on the content of the first information and the second information.

20. The method of claim 18 wherein:

determining (800, YES) that the first information indicates that a coverage enhancement level of a second cell of the second RAT is better than a coverage enhancement level of a first cell of the first RAT, where the second cell of the second RAT operates within a bandwidth of the first cell of the first RAT;

determining (802, YES) that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are the same and/or comprises additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT; and

acquiring (708) system information comprises:

acquiring (804) system information of the second cell of the second RAT; and

using (804) the system information of the second cell of the second RAT to determine at least part of system information of the first cell of the first RAT.

21 . The method of claim 18 wherein:

determining (800, YES) that the first information indicates that a coverage enhancement level of a second cell of the second RAT is better than a coverage enhancement level of a first cell of the first RAT, where the second cell of the second RAT operates within a bandwidth of the first cell of the first RAT;

determining (802, NO) that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are not the same and comprises no additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT; and

acquiring (708) system information comprises directly acquiring (806) system information of the first cell of the first RAT.

22. The method of claim 18 wherein:

determining (800, NO) that the first information indicates that a coverage enhancement level of a second cell of the second RAT is not better than a coverage enhancement level of a first cell of the first RAT, where the second cell of the second RAT operates within a bandwidth of the first cell of the first RAT; and

acquiring (708) system information comprises directly acquiring (806) system information of the first cell of the first RAT.

23. The method of claim 18 wherein:

determining (900, YES) that the first information indicates that a coverage enhancement level of a first cell of the first RAT is better than a coverage enhancement level of a second cell of the second RAT that operates within a bandwidth of the first cell;

determining (902, YES) that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are the same and/or comprises additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT; and

acquiring (708) system information comprises:

acquiring (904) system information of the first cell of the first RAT; and

using (904) the system information of the first cell of the first RAT to determine at least part of system information of the second cell of the second RAT.

24. The method of claim 18 wherein:

determining (900, YES) that the first information indicates that a coverage enhancement level of a first cell of the first RAT is better than a coverage enhancement level of a second cell of the second RAT that operates within a bandwidth of the first cell;

determining (902, NO) that the second information indicates that a SFN of the first cell of the first RAT and a SFN of the second cell of the second RAT are not the same and comprises no additional related information regarding the SFN of the first cell of the first RAT and the SFN of the second cell of the second RAT; and

acquiring (708) system information comprises directly acquiring (906) system information of the second cell of the second RAT.

25. The method of claim 18 wherein: determining (900, NO) that the first information indicates that a coverage enhancement level of a first cell of the first RAT is not better than a coverage enhancement level of a second cell of the second RAT that operates within a bandwidth of the first cell; and

acquiring (708) system information comprises directly acquiring (906) system information of the second cell of the second RAT.

26. A wireless device (102) for a wireless communication network (100), the wireless device (102) adapted to:

obtain information related to a relationship between one or more parameters between cells of two or more Radio Access Technologies, RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT; and

perform one or more tasks based on the information.

27. The wireless device (102) of claim 26 wherein the wireless device (102) is further adapted to perform the method of any one of claims 2 to 25.

28. A wireless device (102) for a wireless communication network (100), comprising:

at least one transceiver (1 106); and

circuitry (1 100) associated with the at least one transceiver (1 106) operable to:

obtain information related to a relationship between one or more parameters between cells of two or more Radio Access Technologies,

RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT; and

perform one or more tasks based on the information.

29. The wireless device (102) of claim 28 wherein the circuitry (1 100) is further operable to perform the method of any one of claims 2 to 25.

30. A wireless device (102) for a wireless communication network (100), comprising:

one or more modules comprising:

an obtaining module (1200) operable to obtain information related to a relationship between one or more parameters between cells of two or more Radio Access Technologies, RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT; and

a performing module (1200) operable to perform one or more tasks based on the information.

31 . The wireless device (102) of claim 30 wherein the one or more modules are further operable to perform the method of any one of claims 2 to 25.

32. A computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of claims 1 to 25.

33. A carrier containing the computer program of claim 32, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

34. A method of operation of a network node (104, 1300) in a wireless communication network (100), comprising:

providing (604, 1002, 1004), to one or more wireless devices (102), information related to a relationship between one or more parameters between cells of two or more Radio Access Technologies, RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT.

35. The method of claim 34 wherein the information related to the relationship between the one or more parameters between the cells of the two or more RATs comprises information indicating per carrier information on a cell Identity, ID, relation of the two or more RATs.

36. The method of claim 35 further comprising:

determining (602) a relation between cell IDs of cells of the first RAT that operate on a carrier of the first RAT and cell IDs of cells of the second RAT that operate within a bandwidth of the carrier of the first RAT;

wherein providing (604, 1002, 1004) the information related to the relationship between the one or more parameters between the cells of the two or more RATs comprises providing (604), to the one or more wireless devices (102), per carrier information that indicates the relation between the cell IDs of the cells of the first RAT that operate on the carrier of the first RAT and the cell IDs of respective cells of the second RAT that operate within the bandwidth of the carrier of the first RAT.

37. The method of claim 36 wherein the per carrier information comprises a per carrier indicator that indicates whether the cells of the first RAT that operate on the carrier of the first RAT and the respective cells of the second RAT that operate within a bandwidth of the carrier of the first RAT have the same cell ID.

38. The method of claim 36 wherein the per carrier information comprises a per carrier indicator that indicates, for each of one or more sets of cells each comprising a first cell of the first RAT that operates on the carrier of the first RAT and a respective second cell of the second RAT that operates within a bandwidth of the carrier of the first RAT, whether the first cell and the respective second cell have the same cell ID.

39. The method of claim 38 wherein the per carrier indicator is an indication that indicates whether cells of the first RAT that operate on the carrier of the first RAT and respective cells of the second RAT that operate in-band or within a guard band of the carrier of the first RAT have the same cell ID.

40. The method of claim 38 wherein the per carrier indicator is an indication that indicates whether cells of the first RAT that operate on the carrier of the first RAT and respective cells of the second RAT that operate in-band, within a guard band, or in-band or within a guard band of the carrier of the first RAT have the same cell ID.

41 . The method of claim 36 wherein the per carrier information comprises a per carrier indicator that indicates an offset between cells IDs of cells of the first RAT that operate on the carrier of the first RAT and respective cells of the second RAT that operate within the bandwidth of the carrier of the first RAT.

42. The method of claim 36 wherein the per carrier information on the cell ID relation of the two or more RATs comprises a per carrier indicator that indicates, for each of one or more sets of cells each comprising a first cell of the first RAT that operate on the carrier of the first RAT and a respective second cell of the second RAT that operates within a bandwidth of the carrier of the first RAT, an offset between a cell IDs of first cell and the respective second cell.

43. The method of any one of claims 35 to 42 further comprising receiving (606) measurement results from the wireless device (102).

44. The method of any one of claims 35 to 43 further comprising determining (600) whether the wireless device (102) is capable of receiving signals of multiple RATs.

45. The method of claim 35 wherein providing (604, 1002, 1004) the information related to the relationship between the one or more parameters between the cells of the two or more RATs comprises: signaling (1002), to the one or more wireless devices (102), first information related to a relation between a coverage enhancement level of cells of the two or more RATs; and

signaling (704), to the one or more wireless devices (102), second information related to a relation between SFNs of cells of the two or more RATs.

46. A network node (104, 1300) for a wireless communication network (100), the network node (104, 1300) adapted to:

provide, to one or more wireless devices (102), information related to a relationship between one or more parameters between cells of two or more Radio Access Technologies, RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT.

47. The network node (104, 1300) of claim 46 wherein the network node (104, 1300) is further adapted to perform the method of any one of claims 35 to 45.

48. A network node (104, 1300) for a wireless communication network (100), comprising:

at least one processor (1304, 1404); and

memory (1306, 60) storing instructions executable by the at least one processor (1304, 1404) whereby the network node (104, 1300) is operable to:

provide, to one or more wireless devices (102), information related to a relationship between one or more parameters between cells of two or more Radio Access Technologies, RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT.

49. The network node (104, 1300) of claim 48 wherein the network node (104, 1300) is further operable to perform the method of any one of claims 35 to 47.

50. A network node (104, 1300) for a wireless communication network (100), comprising:

one or more modules (1500) comprising:

a providing module operable to provide, to one or more wireless devices (102), information related to a relationship between one or more parameters between cells of two or more Radio Access Technologies, RATs, wherein the two or more RATs comprise a first RAT and a second RAT that operates within a bandwidth of the first RAT.

51 . The network node (104, 1300) of claim 50 wherein the one or more modules are further operable to perform the method of any one of claims 35 to 45.

52. A computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of claims 34 to 45.

53. A carrier containing the computer program of claim 52, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.