Prach configuration for multiple trp

Abstract

A method performed by a UE in a wireless communication network is disclosed in which the UE is configured with two TAGs and with a first CORESET associated with a first CORESET pool index and a second CORESET associated with a second CORESET pool index. The method comprises: receiving a first RACH configuration associated with a first PCI for CFRA, the first PCI being associated with a first CORESET; receiving one or more second RACH configurations associated with one or more corresponding second PCIs for the CFRA, where the one or more second PCIs are associated with a second CORESET; receiving an indication of an activated second PCI of the one or more second PCIs and a request for a CFRA associated with the activated second PCI; and performing CFRA according to one of the one or more second RACH configurations associated with the activated second PCI, and performing CFRA according to one of the one or more second RACH configurations associated with the activated second PCI.

Description

[0001] Related Applications

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 457,331, filed April 5, 2023, entitled “PRACH CONFIGURATION FOR MULTI-TRP,” the disclosure of which is incorporated by reference herein in its entirety. TECHNICAL FIELD

[0003] The present disclosure relates to wireless communication networks, and in particular, to a method of performing contention-free random access in a wireless communication network. BACKGROUND

[0004] In a wireless communication network, different user equipments (e.g., user equipments or UEs) in the same cell can typically be located at different positions within the cell and at different distances from the base station (e.g., a gNodeB in a New Radio, NR, communication system). Thus, transmissions from different UEs can suffer different delays before they reach the base station. To ensure that uplink (UL) transmissions from the UEs reach the base station within a corresponding reception window for the base station, an uplink timing control procedure is used. This can help to avoid intra-cell interference both between UEs allocated to transmit in consecutive subframes and between UEs transmitting on adjacent subcarriers.

[0005] The time alignment of the uplink transmissions is achieved by applying a timing advance at the UE transmitter with respect to the received downlink timing. Its main role is to cancel the different propagation delays between different UEs, as illustrated in FIG. 1 for an eNodeB in a Long Term Evolution (LTE) communication system. In particular, FIG. 1 illustrates the time alignment of the uplink transmissions for the case without timing advance (a) and for the case with timing advance (b). Figure 1 Figure 1 The time alignment of the uplink transmissions is achieved by applying a timing advance at the UE transmitter with respect to the received downlink timing. Its main role is to cancel the different propagation delays between different UEs, as illustrated in FIG. 1 for an eNodeB in a Long Term Evolution (LTE) communication system. In particular, FIG. 1 illustrates the time alignment of the uplink transmissions for the case without timing advance (a) and for the case with timing advance (b).

[0006] To achieve the time alignment and thus UL synchronization, the base station (e.g., gNodeB, eNodeB) derives a timing advance (TA) value that the UE needs for UL transmissions to reach the base station within the reception window and indicates it to the UE. When the UE first accesses the cell, it uses a random access procedure, where the base station uses the received Msg1 (Physical Random Access Channel, PRACH, preamble) to determine the initial TA for the UE for UL transmissions in the cell. During the connection, the base station then continuously monitors whether the UE needs to advance / delay the UL transmissions in order to compensate for changes in the propagation delay and indicates to the UE whether the timing advance value needs to be changed.

[0007] Initial timing advance and timing advance group (TAG) configuration ​

[0008] An initial TA value is obtained when the UE performs random access, e.g., when performing a transition from IDLE (or INACTIVE) to CONNECTED state. The initial timing advance is set by the UE transmitting a random access preamble after the UE has first synchronized its receiver to a downlink transmission received from a gNodeB, e.g., by monitoring a synchronization signal block (SSB) of a cell the UE wants to access, the gNodeB estimates an uplink timing value contained within a random access response (RAR) message from the random access preamble. This allows the timing advance to be configured by the gNodeB.

[0009] Physical RACH procedure

[0010] Prior to initiating the physical random access procedure, Layer 1 (physical layer) receives a set of synchronization signal / physical broadcast channel (SS / PBCH) block indices from higher layers and provides a corresponding set of reference signal received power (RSRP) measurements to higher layers.

[0011] The physical random access procedure is triggered when a physical random access channel (PRACH) transmission is requested by higher layers or by a physical downlink control channel (PDCCH) order. The configuration for PRACH transmission by higher layers includes the following:

[0012] • The configuration for PRACH transmission according to [1].

[0013] • Preamble index, preamble subcarrier spacing (SCS), PRACH target receive power, corresponding random access channel radio network temporary identifier (RA-RNTI), and PRACH resource.

[0014] The PRACH preamble is transmitted according to the PRACH configuration on the indicated PRACH resource with the transmission power.

[0015] The PRACH configuration can be cell-specific or UE-specific. The cell-specific PRACH configuration is via the RACH-ConfigCommon information element (IE), while the UE-specific PRACH configuration is via the RACH-ConfigDedicated IE, both described in [2].

[0016] For Type 1 random access procedure, the UE is provided with the total number of PRACH preambles N preamble total If not configured, the default is N preamble total= 64. The UE is also provided with the number of synchronization signal / physical broadcast channel (SS / PBCH) block indexes N associated with one PRACH occasion and the number of contention-based preambles R per SS / PBCH block index per valid PRACH occasion by a parameter called ssb-perRACH-OccasionAndCB-PreamblesPerSSB included in the RACH-ConfigCommon IE.

[0017] If N < 1, one SS / PBCH block index is mapped to 1 / N consecutive valid PRACH occasions and the R contention-based preambles with consecutive indices associated with the SS / PBCH block index per valid PRACH occasion start from preamble index 0. Figure 2 An example is shown where N = 1 / 2, R = 32, N preamble total = 64, and 4 SSBs.

[0018] Figure 2 An example of SSB to PRACH preamble mapping is shown for N = 1 / 2 and R = 32.

[0019] If N ≥ 1, the R contention-based preambles with consecutive indices associated with the SS / PBCH block index n (0 ≤ n ≤ N - 1) per valid PRACH occasion start from preamble index n(N preamble total ) / N. Figure 3 An example is shown where N = 4, R = 4, N preamble total = 64, and 4 SSBs. For each PRACH occasion, PRACH preambles 0 to 3 are allocated to SSB #0 for CBRA, PRACH preambles 4 to 15 are allocated to SSB #0 for CFRA, PRACH preambles 16 to 19 are allocated to SSB #1 for CBRA, and PRACH preambles 20 to 31 are allocated to SSB #1 for CFRA, and so on. Figure 3 An example of SSB to PRACH preamble mapping is shown for N = 4 and R = 4.

[0020] The association of CFRA preamble to SSB can also be reconfigured via the higher parameter ssb-perRACH-Occasion in the RACH-ConfigDedicated IE, in which the UE is provided with information about the number N of SS / PBCH block indices associated with one PRACH occasion. The UE can also be provided with information about the mapping between SSB or channel state information reference signal (CSI-RS) indices and preamble indices in the PRACH occasion.

[0021] PDCCH order initiated RACH procedure

[0022] A RACH procedure can be initiated by a gNodeB or a UE. It can be contention based (CB) or contention free (CF). A RACH procedure can be initiated by a physical downlink control channel (PDCCH) order sent from a gNodeB to a UE in UL time alignment can have been lost for synchronizing the UL. The PDCCH order is carried by a downlink control information (DCI) format 1-0 when the cyclic redundancy code (CRC) of the DCI is scrambled with the cell radio network temporary identifier (C-RNTI) of the UE and the “Frequency domain resource assignment” field of the DCI contains all ones. The PDCCH order contains the following information:

[0023] • Random access preamble index: 6 bits according to the higher layer parameter “ra-PreambleIndex” in clause 5.1.2 of [3].

[0024] • SS / PBCH index: 6 bits, if the value of “Random Access Preamble index” is not all zeros, this field indicates the SS / PBCH that should be used to determine the RACH occasion for PRACH (Physical Random Access Channel) transmission; otherwise, this field is reserved.

[0025] • PRACH mask index. According to clause 5.1.1 of [3], if the value of “Random Access Preamble index” is not all zeros, this field indicates the RACH occasion for PRACH transmission associated with the SS / PBCH indicated by “SS / PBCH index”; otherwise, this field is reserved.

[0026] If the PRACH preamble index is non-zero, a contention free random access (CFRA) procedure is triggered, in which the PRACH preamble is only allocated for the UE in the corresponding PRACH resource.

[0027] If the PRACH preamble index is zero and CFRA PRACH resources associated with SSBs have been provided in the rach-ConfigDedicated IE in the UE-specific RACH configuration, the UE first selects an SSB with a reference signal received power (SS-RSRP) above a configured threshold, and then selects a PRACH preamble according to the selected SSB. If the PRACH preamble index is zero and CFRA resources associated with CSI-RS have been provided in the rach-ConfigDedicated IE, the UE first selects a CSI-RS with a CSI-RSRP above a configured threshold rsrp-ThresholdCSI-RS, and then selects a PRACH preamble according to the selected CSI-RS. If the PRACH preamble index is zero and CFRA PRACH resources associated with SSBs or CSI-RS are not provided, the CBRA procedure is triggered by the PDCCH order, where the UE randomly selects a PRACH preamble from a set of PRACH preambles configured for CBRA in the serving cell. Note that in this case the same preamble can be selected by more than one UE in the same PRACH resource and contention can occur. If a cell group is configured, the PDCCH order triggered CBRA is only allowed for the SpCell, i.e. the primary cell in the master cell group (MCG) or secondary cell group (SCG). The rach-ConfigDedicated IE is described in [2] and the detailed procedure is described in clause 5.1.2 of [3].

[0028] If the UE is configured with two UL carriers for the serving cell and the UE detects a PDCCH order, the UE uses the UL / SUL indicator field value from the detected PDCCH order to determine the UL carrier for the corresponding PRACH transmission.

[0029] A RACH occasion is a time-frequency resource, i.e. a number of RBs in a number of orthogonal frequency-division multiplexing (OFDM) symbols, allocated for PRACH transmission, a number of RACH occasions can be configured in a PRACH configuration period consisting of a number of radio frames. RACH occasions can be multiplexed in time or in frequency.

[0030] From a physical layer perspective, the random access procedure triggered by a PDCCH order includes the transmission of a random access preamble (Msgl) by the UE in the PRACH, the transmission of a random access response (RAR) message and a corresponding physical downlink shared channel (PDSCH) (Msg2) with a PDCCH, and, if applicable, the transmission of a physical uplink shared channel (PUSCH) scheduled by the RAR UL grant, and, if the RACH procedure is contention-based, the transmission of a PDSCH for contention resolution.

[0031] Multi-TRP

[0032] In 3GPP Rel-17, the work done in Rel-16 for multi-TRP is being extended to inter-cell scenarios. Multi-Transmission-Receive Point (mTRP) transmission is essentially a non-coherent joint transmission (NC-JT) over multiple transmission and reception points (TRPs). NC-JT refers to multiple-input multiple-output (MIMO) data transmission over multiple TRPs, where different MIMO layers are transmitted on different TRPs. Two ways of scheduling NC-JT multi-TRP transmission are specified in NR Rel-16: multi-PDCCH based multi-TRP transmission and single-PDCCH based multi-TRP transmission.

[0033] Multi-PDCCH based multi-TRP transmission

[0034] In Figure 4 an example is shown, Figure 4 An example of multi-PDCCH based multi-TRP transmission with a single scheduler is shown. In Figure 4 data is transmitted to the UE over two TRPs, each carrying one transport block (TB) mapped to one codeword. When the UE has 4 receive antennas and each TRP has only 2 transmit antennas, the UE can support up to 4 MIMO layers, but each TRP can transmit up to 2 MIMO layers. In this case, by transmitting data to the UE over two TRPs, the peak data rate to the UE can be increased because up to 4 aggregated layers from the two TRPs can be used. This is beneficial when the traffic load and thus resource utilization is low in each TRP. In this example, a single scheduler is used to schedule data over both TRPs.

[0035] One PDCCH is transmitted in a slot from each of the two TRPs, each TRP scheduling one PDSCH. This is referred to as a multi-PDCCH or multi-DCI scheme, where the UE receives two PDCCHs and associated two PDSCHs in a slot from the two TRPs.

[0036] In Figure 5 another scenario shown,Figure 5 An example of multi-PDCCH based multi-TRP transmission with independent schedulers is shown. In this case, due to non-ideal backhaul, i.e., backhaul with large delay and / or delay variation comparable to the length of cyclic prefix or even longer in some cases (up to several milliseconds), only semi-static to semi-dynamic coordination between the two schedulers can be done.

[0037] Although Figure 4 And Figure 5 Multi-DCI scheduling for PDSCH is shown, but multi-DCI scheduling for PUSCH is also supported in NR Rel-16. In NR Rel-16, multi-DCI scheduling is for multi-TRP, where a UE can receive two DCIs, each scheduling a PDSCH / PUSCH. Each PDCCH and PDSCH is transmitted from the same TRP. In Figure 6 An example is shown in Figure 6 An example of PDSCH transmission with multi-DCI with multiple TRPs is shown. In Figure 6 PDSCH 1 is scheduled by PDCCH 1 from TRP 1 and PDSCH 2 is scheduled by PDCCH 2 from TRP 2. The two PDSCHs can be fully, partially, or not overlapping in time and frequency. When the two PDSCHs are fully or partially overlapping, the same demodulation reference signal (DMRS) resource configuration is assumed, where the DMRS ports of the two PDSCHs are in different code division multiplexing (CDM) groups. Multi-DCI scheduling can also be used to schedule PUSCHs towards different TRPs. In the case of PUSCH scheduling, in NR Rel-16, PUSCH transmissions towards different TRPs are time division multiplexed. In NR Rel-18, multi-DCI based multi-TRP is extended to the case where two PDCCHs from TRP 1 and TRP 2 schedule PUSCH 1 and PUSCH 2, respectively, where PUSCH 1 and PUSCH 2 can be transmitted by the UE simultaneously in overlapping OFDM symbols in time domain.

[0038] For multi-DCI operation, a UE needs to be configured with two control resource set (CORESET) pools, each CORESET pool associated with a TRP. Each CORESET pool is a set of CORESETs belonging to the same pool. A CORESET pool index can be configured with a value of 0 or 1 in each CORESET. For the two DCIs in the above example, they are transmitted in two CORESETs belonging to different CORESET pools (i.e., with CORESETPoolIndex 0 and 1, respectively). The two PDSCHs belong to two different hybrid automatic repeat request (HARQ) processes.

[0039] Inter-cell multi-TRP transmission

[0040] In Rel-17, the concept of “inter-cell” mTRP was introduced. The term is used in quotes here because what is introduced is not “inter-cell” in the sense of serving cell, but “inter-cell” in the sense of SSB set / Physical Cell Identity (PCI). That is, a list of SSBs with different PCI(s) than the PCI of the serving cell is introduced within the serving cell configuration.

[0041] The inter-cell aspect of Rel-17 refers to the case where the two TRPs are associated with different SSBs associated with different PCIs. That is, the TCI states involved in transmissions from TRP 1 or TRP 2 are quasi co-located to a reference signal that is either one SSB beam with a PCI belonging to that TRP, or another reference signal such as CSI-RS or DMRS with a root quasi co-location assumption to one SSB beam with a PCI belonging to that TRP.

[0042] In the case of one TRP associated with a PCI different from the PCI of the serving cell, the different PCI is also referred to as an additional PCI and is provided to the UE through the higher layer parameter “additionalPCI-r17” in the SSB-MTC-AdditionalPCI-r17 IE shown below according to [2]. The SSB-MTC-AdditionalPCI-r17 IE shown in Table 1 also provides information of SSBs associated with the additional PCI.

[0043] Table 1 - SSB-MTC-AdditionalPCI-r17 IE

[0044]

[0045] For a UE in a serving cell, multiple SSB-MTC-AdditionalPCI-r17 IEs can be configured, each associated with an additional PCI. Each of the multiple SSB-MTC-AdditionalPCI-r17 IEs is assigned an index “AdditionalPCIIndex-r17” with a range from 1 to the maximum number of additional PCIs that can be configured. The multiple SSB-MTC-AdditionalPCI-r17 IEs can be configured in “additionalPCI-ToAddModList-r17” in the ServingCellConfig IE shown in Table 2 according to [2].

[0046] Table 2 - ServingCellConfig IE

[0047]

[0048] PRACH dedicated

[0049] PRACH configuration is provided to the UE in the CellGroupConfig IE, which is used to configure either the MCG or the SCG. A cell group comprises one medium access control (MAC) entity, a set of logical channels with associated RLC entities, a primary cell (SpCell) and one or more secondary cells (SCells).

[0050] Within this IE, the PRACH configuration is given in the IE ReconfigurationWithSync. The IE RACH-ConfigDedicated is used to specify dedicated random access parameters. SUMMARY

[0051] Some embodiments provide efficient configuration options for UEs with RACH configuration when the UE is configured with mTRP operation and configured with additional PCIs and two timing advance timer / timing advance group (TAG) groups per serving cell.

[0052] In particular, some embodiments provide a method performed by a UE in a wireless communication network. The UE is configured with two TAGs and configured with a first CORESET associated with a first CORESET pool index and a second CORESET associated with a second CORESET pool index. The method comprises: receiving a first RACH configuration associated with a first PCI for CFRA, wherein the first PCI is associated with the first CORESET; receiving one or more second RACH configurations associated with one or more respective second PCIs for CFRA, wherein the one or more second PCIs are associated with the second CORESET; receiving an indication of an activated second PCI of the one or more second PCIs and a request for CFRA associated with the activated second PCI; and performing the CFRA according to one of the one or more second RACH configurations associated with the activated second PCI.

[0053] Some further embodiments provide a method performed by a UE in a wireless communication network, the method comprising: receiving a first RACH configuration for CFRA to a first PCI associated with a first CORESET, the first CORESET being associated with a first CORESET pool index; and performing CFRA towards a second PCI using the first RACH configuration for multi-TRP operation.

[0054] Some embodiments provide a method performed by a network node in a wireless communication network. The method comprises configuring, to a UE, a first RACH configuration for CFRA of a first PCI associated with a first CORESET, the first CORESET being associated with a first CORESET pool index; and configuring, to the UE, a plurality of second RACH configurations for a respective second plurality of PCIs associated with a second CORESET for multi-TRP operation, the second CORESET being associated with a second CORESET pool index.

[0055] Some further embodiments provide a method performed by a network node in a wireless communication network, the method comprising configuring, to a UE, a RACH configuration for CFRA of a first PCI associated with a first CORESET, the first CORESET being associated with a first CORESET pool index; and configuring, to the UE, a configuration for a second PCI associated with a second CORESET for multi-TRP operation. The UE applies the RACH configuration when performing CFRA of the second PCI for multi-TRP operation.

[0056] Some embodiments also provide a wireless device / UE and a network node for performing the above methods. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 Time alignment of uplink transmission is shown for the case without timing advance (a) and for the case with timing advance (b).

[0058] Figure 2 An example of SSB to PRACH preamble mapping is shown for N=1 / 2 and R=32.

[0059] Figure 3 An example of SSB to PRACH preamble mapping is shown for N=4 and R=4.

[0060] Figure 4 An example of multi-PDCCH based multi-TRP transmission with a single scheduler is shown.

[0061] Figure 5 An example of multi-PDCCH based multi-TRP transmission with independent schedulers is shown.

[0062] Figure 6 An example of PDSCH transmission with multi-DCI with multiple TRPs is shown.

[0063] Figure 7 Details of contention free preamble (CFPR) to SSB mapping are shown.

[0064] Figure 8Aand Figure 8B is a signal flow diagram illustrating message flow and associated operations according to some embodiments.

[0065] Figure 9A and Figure 9B A method performed by a UE in a wireless communication network is shown.

[0066] Figure 10A and Figure 10B A method performed by a network node in a wireless communication network is shown.

[0067] Figure 11 An example of a communication system according to some embodiments is shown.

[0068] Figure 12 A UE according to some embodiments is shown.

[0069] Figure 13 A network node according to some embodiments is shown.

[0070] Figure 14 is a block diagram of a host according to some embodiments. DETAILED DESCRIPTION

[0071] For multi-DCI based inter-cell multi-TRP operation with two TA enhancements, one additional PRACH configuration is supported for each configured additional PCI. The additional PRACH configuration is used in RACH procedure triggered by PDCCH order for the corresponding configured additional PCI.

[0072] However, how to extend the configuration to multi-TRP where the serving cell is configured with two timing advance values / timing advance group is an open question. The RAN1 3GPP group has agreed to have one additional PRACH configuration for each configured additional PCI. However, from the RAN2 3GPP group perspective, the RACH procedure for any additional PCI / SSB is towards the same MAC entity as the original PCI / SSB. Therefore, it can not be feasible to add the entire PRACH configuration for each configured additional PCI.

[0073] Certain aspects of the present disclosure and their embodiments can provide solutions to these or other challenges. Some embodiments described herein provide efficient methods for configuring RACH configuration to a UE when the UE is configured with mTRP operation and configured with additional PCI and two timing advance timer / TAG groups per serving cell.

[0074] For example, in some embodiments, the original RACH configuration provided to the UE for contention-free random access can be applied to the TRP using the additional PCI's SSB. Note that up to 7 additional PCI / SSB can be configured for a UE. One additional PCI / SSB can be active at the time and associated with the second TRP, while the first TRP is associated with the original PCI / SSP of the serving cell.

[0075] Certain embodiments can provide one or more of the following technical advantages. Rather than simply repeating the RACH-ConfigDedicated configuration, other options for configuration are provided. Signaling can be more efficient, as some fields and parameters can be shared among, for example, the additional PCI / SSB configured for the UE. Another advantage is that when not reusing the existing RACH configuration, there is no need to modify the specification text in the existing procedure chapter (e.g., clause 5.3.5.8.3 of [2]), and thus can reduce the difficulty related to backward compatibility.

[0076] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. The embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0077] In a first embodiment, the original RACH configuration provided to the UE for contention-free random access is applied to the TRP using the additional PCI's SSB. Note that up to 7 additional PCI / SSB can be configured for a UE, while one of these additional PCI / SSB is active at the time and associated with the second TRP, while the first TRP is associated with the original PCI / SSP of the serving cell.

[0078] In a variant of the first embodiment, only the root sequence, e.g., configured with prach-RootSequenceIndex, is provided per additional PCI / SSB (respectively for every seven PCI / SSB).

[0079] In a second embodiment, the IE RACH-ConfigDedicated and / or RACH-ConfigCommon is used as-is to give the UE the required additional CFRA configuration for the second TRP. This can be done so that there is one additional CFRA configuration for the second TRP, which can be used regardless of the associated additional PCI / SSB. In a variant, only the root sequence, e.g., configured with prach-RootSequenceIndex, is provided per additional PCI / SSB (respectively for every seven PCI / SSB). In a variant, each additional PCI / SSB receives its own full CFRA configuration.

[0080] In a variant of the second embodiment, the required configuration is given by one sub-IE, such as the CFRA IE.

[0081] In one embodiment, the RACH-ConfigDedicated IE is extended to include additional RACH configuration for a second TRP associated with an additional PCI or separately for each additional PCI / SSB. An example is shown in Table 3. As shown in Table 3, CFRA-Additional configured for an additional PCI contains at least one of the following:

[0082] • a rach-ConfigGeneric field that provides configuration of contention-free random access occasions for CFRA specific to the additional PCI;

[0083] • ssb-perRACH-Occasion that configures the number of SSBs per RACH occasion;

[0084] • prach-RootSequenceIndex that provides the PRACH root sequence index corresponding to the additional PCI;

[0085] • optionally, additionalPCIIndex that is the index of the additional PCI when more than one additional PCI is configured to the UE (e.g., additionalPCIIndex provides an integer index between 1 and X corresponding to the configured cfra-Additional parameter when X number of PCIs are configured);

[0086] • optionally, additionalPCI that provides the physical cell ID PhysCellId corresponding to the additional PCI.

[0087] Note that in an alternative embodiment, additionalPCIIndex and additionalPCI can not be explicitly configured as part of CFRA-Additional. Instead, each CFRA-Additional can be implicitly associated with additionalPCIIndex and additionalPCI parameters configured elsewhere (e.g., additionalPCIIndex and additionalPCI can be configured as part of the SSB-MTC-AdditionalPCI-r17 field as described in [2]).

[0088] Table 3 depicts an embodiment where additionalPCIIndex and additionalPCI are configured as part of SSB-MTC-AdditionalPCI-r17, which shows additional RACH configuration for a second TRP associated with an additional PCI.

[0089] Table 3 - RACH-ConfigDedicated IE

[0090]

[0091] In an alternative embodiment, the RACH-ConfigDedicated IE is extended to include additional RACH configuration associated with additional PCIs, as shown in Table 4 below. In Table 4, a list of CFRA-Additional fields is configured, where each CFRA-Additional field corresponds to one of the list of configured additional PCIs. Note that the list of additional PCIs is configured as part of MIMOParam-r17 in [2], where each additional PCI configures one SSB-MTC-AdditionalPCI-r17. Thus, it can alternatively be stated that each CFRA-Additional field corresponds to one of the configured SSB-MTC-AdditionalPCI-r17. The contents of CFRA-Additional can be similar to the example in Table 3. Note that additionalPCIIndex and additionalPCI can not be explicitly configured as part of CFRA-Additional. Instead, each CFRA-Additional can be implicitly associated with the additionalPCIIndex and additionalPCI parameters, which are configured as part of each of the list of SSB-MTC-AdditionalPCI-r17.

[0092] Table 4 - Second example showing additional RACH configuration for additional TRP(s) associated with additional PCI(s)

[0093]

[0094] In another embodiment, a separate IE associated with each additional PCI can be used to configure CFRA-based PRACH.

[0095] In one embodiment, for PRACH initiated with PDCCH order, the IE CFRA is extended such that the field rach-ConfigGeneric is common for the original configuration and one or more TRPs associated with the additional PCI(s). In this embodiment, the number of SSBs per RACH occasion (given by the parameter ssb-perRACH-Occasion2-r18) corresponding to each RACH occasion for the additional PCI can be configured as part of the extended CFRA, as shown in Table 5. When more than one additional PCI is configured, alternatively, a list of ssb-perRACH-Occasion2-r18 parameters can be configured as part of the CFRA IE, where each ssb-perRACH-Occasion2-r18 in the list provides the number of SSBs per RACH occasion corresponding to each of the additional PCI(s) in the list of additional PCIs configured to the UE.

[0096] Table 5 - First example showing extension of CFRA configuration for the second TRP associated with the additional PCI

[0097]

[0098] In one embodiment, for PRACH initiated with PDCCH order, the IE CFRA is extended such that both rach-ConfigGeneric and ssb-perRACH-Occasion are different between the first TRP and the TRP associated with the additional PCI. Table 6 shows an example of this extension. In this embodiment, rach-ConfigGeneric and ssb-perRACH-Occasion corresponding to the additional PCI can be configured as part of the extended CFRA, as shown in Table 6. When more than one additional PCI is configured, alternatively, a list of ssb-perRACH-Occasion-r18 parameters can be configured as part of the CFRA IE, where each ssb-perRACH-Occasion-r18 in the list provides the number of SSBs per RACH occasion corresponding to each of the additional PCI(s) in the list of additional PCIs configured to the UE. When more than one additional PCI is configured, alternatively, a list of rach-ConfigGeneric-r18 parameters can be configured as part of the CFRA IE, where each rach-ConfigGeneric-r18 in the list provides the configuration of CFRA corresponding to each of the additional PCI(s) in the list of additional PCIs configured to the UE.

[0099] Additionally, as shown in Table 6, the PRACH root sequence index prach-RootSequenceIndex-r18 corresponding to the additional PCI can be configured as part of the extended CFRA. When more than one additional PCI is configured, alternatively, a list of prach-RootSequenceIndex-r18 parameters can be configured as part of the CFRA IE, where each prach-RootSequenceIndex-r18 in the list provides a PRACH root sequence index corresponding to each of the additional PCI(s) in the list of additional PCIs configured to the UE.

[0100] In some alternative embodiments, the additionalPCIIndex and additionalPCI can be explicitly configured as part of the extended CFRA configuration. Alternatively, the additionalPCIIndex and additionalPCI can not be explicitly configured as part of the extended CFRA configuration. Instead, each of the extended elements (e.g., any one or more of rach-ConfigGeneric-r18, ssb-perRACH-Occasion-r18, and prach-RootSequenceIndex-r18) can be implicitly associated with the additionalPCIIndex and additionalPCI parameters configured elsewhere (e.g., the additionalPCIIndex and additionalPCI can be configured as part of the SSB-MTC-AdditionalPCI-r17 field as described in [2]).

[0101] Table 6 - Second example of extending the CFRA IE for additional PCI(s)

[0102]

[0103] In one embodiment, for UE initiated PRACH, if the UE is configured with an additional PCI / SSB, the IE CFRA-SSB-Resource used in the IE PRACH-ConfigDedicated is extended with an additional PCI index, as shown in Table 7.

[0104] Table 7 - CFRA-SSB-Resource IE

[0105]

[0106] In Table 7, additionalPCI indicates the physical cell ID (PCI) of the SSB. It refers to the PCI value configured in the configured list additionalPCI-ToAddModList in the serving cell in which the UE performs RACH.

[0107] To extend the CSI-RS resource for PRACH, there are two options. In the first option, a non-zero power (NZP) CSI-RS id is used, which enables association of any NZP CSI RS configured for the serving cell, which means such NZP CSI-RS can also be associated with additionalPCI in the TCI state configuration, as shown in Table 8.

[0108] Table 8 - CFRA-CSIRS-Resource IE

[0109]

[0110] In the second option, the CSI-RS defined in the measurement object is extended, as shown in Table 9.

[0111] Table 9 - CSI-RS-ResourceConfigMobility IE

[0112]

[0113] In Table 9, additionalPCI indicates the PCI of the SSB for associatedSSB. It refers to the PCI value configured in the configured list additionalPCI-ToAddModList in the serving cell in which the UE performs RACH.

[0114] In another embodiment, for additional PCI, the PRACH configuration is not extended, but it is specified that when the UE receives a PDCCH order involving a TRP associated with the additional PCI, the UE applies the original PRACH configuration for that PCI / SSB / TRP. The PRACH configuration can be dedicated or common. The dedicated or common original PRACH configuration can be the PRACH configuration given for the cell group to which the TRP associated with the PDCCH order belongs.

[0115] In a third embodiment, the first TRP associated with the serving cell PCI / SSB uses the original CFRA configuration and the second TRP receives the RACH configuration using the IE BeamFailureRecoveryConfig. Similar to embodiments 1 and 2, every 7 additional PCI / SSB can receive its own RACH configuration or just the root sequence. In a variant, the first TRP also receives additional CFRA configuration using the IE BeamFailureRecoveryConfig.

[0116] In another embodiment, the TRP can use the beamfailurerecovery configuration to be associated with the PRACH configuration. This configuration can be implicit such that the UE assumes the same configuration as configured for beam failure recovery. Or, it can be a new field using the IE BeamFailureRecoveryConfig. The PCI linked with the SSB pointed in this configuration is assumed to be the PCI currently active for the second TRP. For the first TRP, the PCI is the PCI of the original serving cell.

[0117] In a fourth embodiment, the first TRP associated with the serving cell PCI / SSB uses the original CFRA configuration and the second TRP receives the RACH configuration using a new IE. Similar to the first and second embodiments, every 7 additional PCI / SSB can receive its own RACH configuration or just the root sequence. In a variant, the first TRP also receives additional CFRA configuration using the new IE. Details of the new IE are given below.

[0118] In one embodiment, a new configuration IE is defined with which the UE is configured with SSB and RACH resources to regain UL time synchronization per TRP in case of expiry of the associated time alignment timer. This configuration is not specific to a PCI / SSB but applies to any additional PCI / SSB active. In a variant, the same configuration applies to the TRP associated with the original PCI of the serving cell.

[0119] This new IE contains one or more higher layer parameters or IEs that can be configured for CFRA based PRACH transmission associated with additional PCIs. Such higher layer parameters can include a PRACH root sequence index or a CFRA IE. The CFRA IE can include a RACH-ConfigGeneric IE, a ssb-perRACH-Occasion, a CFRA-SSB-Resource IE, and / or a CFRA-CSIRS-Resource IE.

[0120] Table 10 shows another example of this new IE.

[0121] Table 10 - RACH-ConfigAdditional IE

[0122]

[0123] With this IE, the UE can be configured with RACH resources for two TRPs or a second TRP, e.g., in the servingcellConfig IE. Optionally, if the configuration is cell group specific, it can be given in the cell group configuration in the IE CellGroupConfig. Optionally, the configuration can be common for TRPs following the same TAG ID of the serving cell configured for the UE.

[0124] In a fifth embodiment, related to the third and fourth embodiments, when one TRP-specific timing advance timer expires, the UE uses the RACH configuration given in the IE BeamFailureRecoveryConfig or in a new IE. When both timers expire, the UE uses the original CFRA configuration.

[0125] In a sixth embodiment, related to the third and fourth embodiments, the UE can receive a PDCCH order to use the RACH configuration given in the IE BeamFailureRecoveryConfig or in a new IE. The UE can also receive a PDCCH order to use the original CFRA configuration.

[0126] In one embodiment, for intra-cell cases, the SSB of the original serving cell is associated / shared to TRP1 and TRP2.

[0127] In one embodiment, the ssb-perRACH-OccasionAndCB-PreamblesPerSSB parameter in the rach-ConfigCommon IE includes a new IE, e.g., ssbAdditionalPerRachOccasionAndCF-Preambles-r18, additional SSBs are signaled to be available such that for shared RACH occasions, the SSBs (e.g., available for CFRA) are extended. In this way, additional SSBs (for additional TRPs / PCIs) can be configured and the total number of preambles per corresponding CFRA SSB can be divided and configured.

[0128] Table 11 - BWP-UplinkCommon IE

[0129]

[0130] Figure 7 Details of contention free preamble (CFPR) to SSB mapping for PRACH index = 1 and 4-step RACH procedure are shown.

[0131] Figure 8A is a signal flow diagram illustrating a message flow according to some embodiments, Figure 9A A method performed by a UE 1200 in a wireless communication network is shown. Reference is made to Figure 8A and Figure 9A The UE 1200 is configured with two TAGs and is configured with a first CORESET associated with a first CORESET pool index and a second CORESET associated with a second CORESET pool index. The method comprises receiving (block 902) a first RACH configuration 802 associated with a first PCI for CFRA, wherein the first PCI is associated with the first CORESET.

[0132] At block 904, the UE receives one or more second RACH configurations 804 associated with one or more respective second PCIs for CFRA, wherein the one or more second PCIs are associated with the second CORESET. The first and second RACH configurations have been described earlier.

[0133] At block 906, the UE receives an indication 806 of an activated second PCI of the one or more second PCIs and a request for CFRA associated with the activated second PCI. In response to receiving the indication, at block 908, the UE performs CFRA according to one of the one or more second RACH configurations associated with the activated second PCI.

[0134] Figure 8B is a signal flow diagram illustrating a message flow according to further embodiments, Figure 9B Operation of a method performed by a UE 1200 in a wireless communication network according to further embodiments is shown. Reference is made to Figure 8B and Figure 9B The UE receives (block 912) a first RACH configuration 812 for CFRA to a first physical cell identification, PCI, associated with a first CORESET, the first CORESET being associated with a first CORESET pool index. The UE performs (block 914) CFRA using the first RACH configuration to a second PCI for multi-TRP operation.

[0135] Figure 10A A method performed by a network node (1300) in a wireless communication network according to some embodiments is shown. Reference is made to Figure 8A and Figure 10A, the network node 1300 configures (block 1002) the UE 1200 with a first RACH configuration 802 for CFRA of a first PCI associated with a first CORESET, the first CORESET being associated with a first CORESET pool index. The network node 1300 configures (block 1004) the UE with a plurality of second RACH configurations 804 for a respective second plurality of PCIs associated with a second CORESET for multi-TRP operation, the second CORESET being associated with a second CORESET pool index. The network node 1300 then transmits (block 1006) an indication 806 of an activated second PCI of the one or more second PCIs and a request for CFRA associated with the activated second PCI.

[0136] Figure 10B Operations of a method performed by a network node 1300 in a wireless communication network are shown in accordance with further embodiments. Reference is made to Figure 8B and Figure 10B , the network node 1300 configures (block 1012) the UE 1200 with a RACH configuration 812 for CFRA of a first PCI associated with a first CORESET, the first CORESET being associated with a first CORESET pool index, and configures (block 1014) the UE with a configuration for a second PCI associated with a second CORESET for multi-TRP operation. The UE applies the RACH configuration when performing CFRA of the second PCI for multi-TRP operation. The RACH configuration and the configuration for the second PCI have been described earlier.

[0137] Figure 11 An example of a communication system 1100 is shown in accordance with some embodiments.

[0138] In an example, the communication system 1100 includes a telecommunication network 1102 that comprises an access network 1104, such as a Radio Access Network (RAN), and a core network 1106 that comprises one or more core network nodes 1108. The access network 1104 comprises one or more access network nodes, such as network nodes 1110a and 1110b (one or more of which can be commonly referred to as network nodes 1110), or any other similar 3GPP access nodes or non-3GPP access points. Also, as those skilled in the art will appreciate, the network nodes are not necessarily limited to implementations in which the radio and baseband portions are provided and integrated by a single vendor. Thus, it will be understood that the network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 1102 includes one or more Open RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 1102 that supports ORAN specifications (e.g., specifications published by the O-RAN Alliance or any similar organization) and can operate alone or in conjunction with other nodes to implement one or more functions of any of the nodes in the telecommunication network 1102 (including the one or more network nodes 1110 and / or core network nodes 1108).

[0139] Examples of ORAN network nodes include an Open Radio Unit (O-RU), an Open Distributed Unit (O-DU), an Open Central Unit (O-CU (including O-CU Control Plane (O-CU-CP) or O-CU User Plane (O-CU-UP)), a RAN Intelligent Controller of (near real-time or non-real-time) hosted software or software plug-ins (such as near real-time control applications (e.g., xApps) or non-real-time control applications (e.g., rApps)), or any combination thereof (the adjective “open” indicates support for ORAN specifications). The network nodes can support the specifications by, for example, supporting interfaces defined by the ORAN specifications, such as Al, Fl, Wl, El, E2, X2, Xn interfaces, an Open Front-haul User Plane interface, or an Open Front-haul Management Plane interface. Also, the ORAN access nodes can be logical nodes in a physical node. Furthermore, the ORAN network nodes can be implemented in a virtualized environment (further described below) in which one or more network functions are virtualized. For example, the virtualized environment can include an O-Cloud computing platform orchestrated by a service management and orchestration framework via an O-2 interface defined by the O-RAN Alliance or comparable technologies. The network nodes 1110 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 1112a, 1112b, 1112c, and 1112d (one or more of which can be commonly referred to as UEs 1112) to the core network 1106 through one or more wireless connections.

[0140] Example wireless communications via wireless connections include the transmission and / or reception of wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information over a distance without the use of wires, cables, or other material conductors. Also, in different embodiments, communication system 1100 can include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that can facilitate or participate in the communication of data and / or signals between and among each other, whether via wired or wireless connections. Communication system 1100 can include any type of communication, telecommunications, data, cellular, radio, and / or other similar type of system and / or interface therewith.

[0141] UE 1112 can be any of a variety of communication devices, including wireless devices arranged, configured and / or operable to communicate wirelessly with network nodes 1110 and other communication devices. Similarly, network nodes 1110 are arranged, capable, configured and / or operable to communicate directly or indirectly with UE 1112 and / or with other network nodes or devices in telecommunication network 1102 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as management in telecommunication network 1102.

[0142] In the depicted example, core network 1106 connects network nodes 1110 to one or more hosts, such as host 1116. These connections can be direct or indirect, such as through one or more intermediary networks or devices. In other examples, a network node can be directly coupled to a host. Core network 1106 includes one or more core network nodes (e.g., core network node 1108) constructed of hardware and software components. The features of these components can be substantially similar to those described with respect to UEs, network nodes, and / or hosts, such that their description generally applies to corresponding components of core network node 1108. Example core network nodes include functionality of one or more of a mobile switching center (MSC), a mobility management entity (MME), a home subscriber server (HSS), an access and mobility management function (AMF), a session management function (SMF), an authentication server function (AUSF), a subscription identifier de-concealing function (SIDF), a unified data management (UDM), a security edge protection proxy (SEPP), a network exposure function (NEF), and / or a user plane function (UPF).

[0143] The host 1116 can be under the ownership or control of a service provider other than the operator or provider of the access network 1104 and / or the telecommunication network 1102, and can be operated by the service provider or on behalf of the service provider. The host 1116 can host various applications to provide one or more services. Examples of such applications include live and pre-recorded audio / video content, data collection services (such as retrieving and compiling data detected by various environmental conditions by a plurality of UEs), analytics functions, social media, functions for controlling or otherwise interacting with remote devices, functions for alarm and monitoring centers, or any other such functions performed by servers.

[0144] In its entirety, Figure 11 The communication system 1100 enables connectivity between the UEs, the network nodes, and the host computer. In this regard, the communication system can be configured to operate according to predefined technical specifications or other specifications, such as specific standards including but not limited to Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term

[0145] In some examples, the telecommunication network 1102 is a cellular network that implements 3GPP-standardized features. Thus, the telecommunication network 1102 can support network slicing to provide different logical networks for different devices connected to the telecommunication network 1102. For example, the telecommunication network 1102 can provide Ultra-Reliable and Low-Latency Communications (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communications (mMTC) / massive IoT services to further UEs.

[0146] In some examples, the UEs 1112 are configured to transmit and / or receive information without direct human interaction. For example, a UE can be designed to transmit information to the access network 1104 on a prearranged schedule, when triggered by an internal or external event, or in response to requests from the access network 1104. In addition, UEs can be configured for operation in single-RAT or multi-RAT or multi- standard mode. For example, UEs can operate using any one or a combination of Wi-Fi, NR, and LTE, i.e., configured for Multi-Radio Dual Connectivity (MR-DC) such as e-UTRA-NR Dual Connectivity (EN-DC).

[0147] In examples, the hub 1114 communicates with the access network 1104 to facilitate indirect communication between one or more UEs (e.g., UEs 1112c and / or 1112d) and a network node (e.g., network node 1110b). In some examples, the hub 1114 can be a controller, router, content source, and analytics, or any other communication device described herein with respect to a UE. For example, the hub 1114 can be a broadband router that enables a UE to access the core network 1106. As another example, the hub 1114 can be a controller that sends commands or instructions to one or more actuators in the UEs. The commands or instructions can be received from the UEs, the network nodes 1110, or by executable code, scripts, processes, or other instructions in the hub 1114. As another example, the hub 1114 can be a data collector that acts as temporary storage for UE data, and in some embodiments, can perform analysis or other processing of the data. As another example, the hub 1114 can be a content source. For example, for a UE that is a VR headset, display, speaker, or other media delivery device, the hub 1114 can retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 1114 then provides directly to the UE after performing local processing and / or after adding additional local content. In yet another example, the hub 1114 acts as a proxy server or orchestrator for the UEs, particularly where one or more of the UEs are low-energy IoT devices.

[0148] The hub 1114 can have a constant / persistent or intermittent connection to the network node 1110b. The hub 1114 can also allow for different communication schemes and / or scheduling between the hub 1114 and UEs (e.g., UEs 1112c and / or 1112d) and between the hub 1114 and the core network 1106. In other examples, the hub 1114 is connected to the core network 1106 and / or one or more UEs via a wired connection. Also, the hub 1114 can be configured to connect to an M2M service provider over the access network 1104 and / or to another UE over a direct connection. In some scenarios, a UE can establish a wireless connection with the network node 1110 while still connecting via the hub 1114 via a wired or wireless connection. In some embodiments, the hub 1114 can be a dedicated hub, that is, a hub whose primary function is to route communications from and to the UE to and from the network node 1110b. In other embodiments, the hub 1114 can be a non-dedicated hub, that is, a device that is capable of operating to route communications between the UE and the network node 1110b, but additionally capable of operating as a communication origination and / or termination point for certain data channels.

[0149] Figure 12 A UE 1200 according to some embodiments is shown. In particular, the UE 1200 can be configured to perform the operations described above in connection with Figure 8A , Figure 8B , Figure 9A and Figure 9B As used herein, a UE refers to a device that is capable, configured, arranged and / or operable to communicate wirelessly with a network node and / or other UEs. Examples include, but are not limited to, smart phones, mobile phones, cellular phones, laptops, laptop-embedded- equipment (LEE), laptop-mounted equipment (LME), smart devices, wireless customer-premises equipment (CPE), vehicles, vehicle-mounted or embedded equipment, etc. Other examples include any UE identified by 3GPP, including Narrowband Internet of Things (NB-IoT) UEs, Machine Type Communication (MTC) UEs, and / or Enhanced MTC (eMTC) UEs.

[0150] A UE can support device-to-device (D2D) communication, such as through implementation of 3GPP standards for sidelink communication, dedicated short range communications (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-anything (V2X). In other examples, a UE can not necessarily have a user in the sense of a human user that owns and / or operates the relevant device. Instead, a UE can represent a device that is intended for sale to, or operation by, a human user, but that can not be associated with a specific human user, or that can initially not be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE can represent a device that is not intended for sale to, or operation by, an end user, but that can be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0151] The UE 1200 includes processing circuitry 1202 that is operatively coupled to an input / output interface 1206, a power source 1208, a memory 1210, a communication interface 1212, and / or any other component(s) or any combination thereof, via bus 1204. Some of the components of UE 1200, or their interfaces, can be stored or implemented in the memory 1210 and / or the processing circuitry 1202, which can include one or more processors and / or one or more computer-readable mediums. Figure 12 All or a subset of the components shown in FIG. 12 can be included in the UE 1200. The level of integration between the components can vary from one UE to another UE. Further, certain UEs can contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0152] The processing circuitry 1202 is configured to process instructions and data, and can be configured to implement any order state machines operable to execute instructions stored in the memory 1210 as a machine-readable computer program. The processing circuitry 1202 can be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field programmable gate array (FPGA), application specific integrated circuit (ASIC), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination thereof. For example, the processing circuitry 1202 can include multiple central processing units (CPUs).

[0153] In an example, the input / output interface 1206 can be configured to provide one or more interfaces to input devices, output devices, or one or more input and / or output devices. Examples of output devices include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device can allow a user to capture information into the UE 1200. Examples of input devices include a touch-sensitive or presence-sensitive display, a camera, a smartcard, and so on. A presence-sensitive display can include a capacitive or resistive touch sensor to sense input from a user. Sensors can be, for example, accelerometers, gyroscopes, tilt sensors, biometric sensors, and so on, or any combination thereof. An output device can use the same type of interface port as an input device. For example, a universal serial bus (USB) port can be used to provide both input and output to the UE 1200.

[0154] In some embodiments, the power source 1208 is configured as a battery or battery pack. Other types of power sources, such as an external power supply (e.g., an electricity outlet), photovoltaic devices or power cells, can also be used. The power source 1208 can further include a power circuit for delivering power from the power source 1208 and / or an external power source to portions of the UE 1200 via an input circuit or interface (such as an electrical cable). The power can be delivered from the power source 1208, for example, for charging the power source 1208. The power circuit can perform any formatting, converting, or other modification to the power from the power source 1208 to make the power suitable for use by

[0155] The memory 1210 can be or include memory such as random access memory (RAM), read only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), a magnetic disk, an optical disk, a hard disk, a removable diskette, a flash drive, and / or the like. In one example, the memory 1210 includes one or more applications 1214, such as an operating system, a web browser application, a widget or widget engine, or other applications, and corresponding data 1216. The memory 1210 can store any of a variety of different operating systems, or combinations of operating systems, for use by the UE 1200.

[0156] Memory 1210 can be configured to include a number of physical drive units, such as Redundant Array of Independent Disks (RAID), flash memory, USB flash drives, external hard drives, thumb drives, pen drives, key drives, High-Density Digital Versatile Disc (HD-DVD) optical disc drives, internal hard disk drives, Blu-Ray optical disc drives, Holographic Digital Data Storage (HDDS) optical disc drives, external mini-dual in-line memory modules (DIMMs), synchronous dynamic random access memories (SDRAM), external micro-DIMMs, smart cards, other memory, or any combination thereof. The UICC can be, for example, an embedded UICC (eUICC), an integrated UICC (iUICC), or a removable UICC commonly referred to as a "SIM card." Memory 1210 can allow UE 1200 to access instructions, application programs, or data stored on transitory or non-transitory memory media for offloading or uploading data. An article of manufacture, such as one utilizing a communication system can be tangibly embodied in or by the memory 1210, which can be or include a device readable storage medium.

[0157] Processing circuitry 1202 can be configured to communicate with an access network or other networks using communication interface 1212. Communication interface 1212 can include one or more communication subsystems and can include or be communicatively coupled to an antenna 1222. The communication interface 1212 can include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node of an access network). Each transceiver can include transmitter 1218 and / or receiver 1220 adapted to provide network communications (e.g., optical, electrical, or frequency allocations). Also, the transmitter 1218 and receiver 1220 can be coupled to one or more antennas (e.g., antenna 1222), and can share circuit components, software, or firmware, or alternatively can be separate components.

[0158] In the illustrated embodiment, the communication functionality of the communication interface 1212 can include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communication such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine location, another similar communication functionality, or any combination thereof. The communication can be implemented in accordance with one or more communication protocols and / or standards, such as IEEE 802.11, code division multiple access (CDMA), wideband code division multiple access (WCDMA), GSM, LTE, NR, UMTS, WiMax, Ethernet, transmission control protocol / Internet protocol (TCP / IP), synchronous optical networking (SONET), asynchronous transfer mode (ATM), QUIC, hypertext transfer protocol (HTTP), and / or the like.

[0159] Regardless of the type of sensor, the UE can provide the output of the data captured by its sensor to a network node via a wireless connection through its communication interface 1212. The data captured by the sensor of the UE can be communicated to a network node via a wireless connection through another UE. The output can be periodic (e.g., every 15 minutes if it reports the sensed temperature), random (e.g., to balance the load of the reports from several sensors), in response to a triggering event (e.g., sending an alarm when moisture is detected), in response to a request (e.g., a user-initiated request), or a continuous stream (e.g., a real-time video feed of a patient).

[0160] As another example, the UE includes an actuator, motor, or switch in relation to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input, the state of the actuator, motor, or switch can change. For example, the UE can include a motor that adjusts a control surface or rotor of a drone in flight according to the received input, or a robotic arm performing a medical procedure according to the received input.

[0161] When in the form of an IoT device, the UE can be a device for use in one or more application areas including, but not limited to, urban wearable technology, extended industrial applications, and healthcare. Non-limiting examples of such IoT devices are the following devices or devices embedded in the following items: a connected refrigerator or freezer, a television, a connected lighting device, and any type of medical device (e.g., a heart rate monitor or a remotely controlled surgical robot). In addition to other components as described with respect to the UE 1200 shown in Figure 12 The UE in the form of an IoT device includes circuitry and / or software dependent on the intended application of the IoT device in addition to other components as described with respect to the UE 1200 shown in

[0162] As yet another specific example, in an IoT scenario, a UE can represent a machine or other device that performs monitoring and / or measurements and sends results of such monitoring and / or measurements to another UE and / or a network node. In this case, the UE can be a M2M device, which in a 3GPP context can be referred to as a MTC device. As one particular example, the UE can implement the 3GPP NB-IoT standard. In other scenarios, the UE can represent a vehicle, such as an automobile, a bus, a truck, a ship, and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0163] In practice, any number of UEs can be used together for a single use case. For example, a first UE can be or be integrated in a drone, and provide speed information (obtained by a speed sensor) of the drone to a second UE that is a remote controller operating the drone. When the user makes a change from the remote controller, the first UE can adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the speed of the drone. The first and / or second UE can also include more than one of the functions described above. For example, the UE can include a sensor and an actuator, and handle communications for data of both the speed sensor and the actuator.

[0164] Figure 13 A network node 1300 according to some embodiments is shown. In particular, the network node 1300 can be configured to perform operations described above in relation to Figure 8A 、 Figure 8B 、 Figure 10A and Figure 10B . As used herein, a network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with another network node or device in a telecommunications network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR Node Bs (gNBs)), O-RAN nodes or components of O-RAN nodes (e.g., O-RUs, O-DUs, O-CUs).

[0165] Base stations can be categorized based on how much power they provide for their coverage (or, stated differently, how large of a coverage area they serve) and thus, depending on that, can be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station can be a relay node or a relay-donating node controlling relays. Network nodes can also comprise one or more (or all) parts of a distributed radio base station such as a centralized, a distributed or a low power node of a base station, or of a radio access network node such as an access node of an O-RAN. Such a remote radio unit can or can not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station can also be referred to as nodes in a distributed antenna system (DAS).

[0166] Other examples of network nodes include multi-TRP 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), operation and maintenance (O&M) nodes, operation support system (OSS) nodes, self-organizing network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Center (E-SMLC)), and / or minimizing drive tests (MDT).

[0167] The network node 1300 includes processing circuitry 1302, memory 1304, communication interface 1306, and power source 1308. The network node 1300 can include a plurality of physically separate components (e.g., NodeB component and RNC component, or BTS component and BSC component, etc.), which can each have their own respective components. In certain scenarios in which the network node 1300 includes multiple separate components (e.g., BTS and BSC components), one or more of the separate components can be shared among several network nodes. For example, a single RNC can control multiple NodeBs. In such scenarios, each unique pair of a NodeB and an RNC, in some instances, can be considered a single separate network node. In some embodiments, the network node 1300 can be configured to support multiple radio access technologies (RATs). In such embodiments, some components can be duplicated (e.g., separate memory 1304 for the different RATs), and some components can be reused (e.g., the same antenna 1310 can be shared by the different RATs). The network node 1300 can also include multiple sets of various shown components for different wireless technologies integrated into the network node 1300, such as GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, radio frequency identification (RFID), or Bluetooth wireless technologies. These wireless technologies can be integrated into the same or different chip or set of chips and other components within the network node 1300.

[0168] The processing circuitry 1302 can comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other processing circuit, as well as any

[0169] In some embodiments, the processing circuitry 1302 comprises a system on a chip (SOC). In some embodiments, the processing circuitry 1302 includes one or more of radio frequency (RF) transceiver circuitry 1312 and baseband processing circuitry 1314. In some embodiments, radio frequency (RF) transceiver circuitry 1312 and baseband processing circuitry 1314 can be on separate chips (or sets of chips), boards, or units, such as a radio unit and a digital unit. In other alternative embodiments, part or all of RF transceiver circuitry 1312 and baseband processing circuitry 1314 can be on the same chip or set of chips, board, or unit.

[0170] Memory 1304 can include any form of volatile or non-volatile computer- readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, RAM, ROM, mass storage media (for example, hard drives), removable memory media (for example, flash drives, CDs, or digital video disks (DVDs)), and / or any other volatile or non-volatile, non-transitory device-readable memory devices that store information, data, and / or instructions that can be used with processing circuitry 1302. Memory 1304 can store any

[0171] Communication interface 1306 is used for wired or wireless communication of signaling and / or data between network nodes, access networks, and / or UEs. As illustrated, communication interface 1306 comprises port(s) / terminal(s) 1316 to send and receive data, for example, to and from a network via a wired connection. Communication interface 1306 also includes radio front end circuitry 1318 that can be coupled to, or in some embodiments a part of, antenna 1310. Radio front end circuitry 1318 comprises filters 1320 and amplifiers 1322. Radio front end circuitry 1318 can be connected to antenna 1310 and processing circuitry 1302. Radio front end circuitry can be configured to condition signals communicated between antenna 1310 and processing circuitry 1302. Radio front end circuitry 1318 can receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. Radio front end circuitry 1318 can convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1320 and / or amplifiers 1322. The radio signal can then be transmitted via antenna 1310. Similarly, when receiving data, antenna 1310 can collect radio signals, which are then converted into digital data by radio front end circuitry 1318. The digital data can be passed to processing circuitry 1302. In other embodiments, the communication interface can comprise different components and / or different combinations of components.

[0172] In certain alternative embodiments, network node 1300 does not include separate radio front-end circuitry 1318, instead, processing circuitry 1302 includes radio front-end circuitry and is connected to antenna 1310. Similarly, in some embodiments, all or some of RF transceiver circuitry 1312 is part of communication interface 1306. In other embodiments, communication interface 1306 includes one or more ports or terminals 1316, radio front-end circuitry 1318, and RF transceiver circuitry 1312 as part of a radio

[0173] Antenna 1310 can include one or more antennas or antenna arrays configured to send and / or receive wireless signals. Antenna 1310 can be coupled to radio front-end circuitry 1318 and can be any type of antenna and / or antenna array capable of

[0174] Antenna 1310, communication interface 1306, and / or processing circuitry 1302 can be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by a network node. Any information, data and / or signals can be received from a UE, another network node and / or any other network equipment. Similarly, antenna 1310, communication interface 1306, and / or processing circuitry 1302 can be configured to perform any transmitting operations described herein as being performed by a network node. Any information, data and / or signals can be transmitted to a UE, another network node and / or any other network equipment.

[0175] Power source 1308 provides power to various components of network node 1300 in a form suitable for use by each respective component (e.g., at a voltage and current level needed for each respective component). Power source 1308 can also include, or be coupled to, power management circuitry to provide power for use by the components of network node 1300 in performing the functions described herein. For example, network node 1300 can be connected to an external power source (e.g., an electricity outlet) via an input circuitry or interface, such as an electrical cable, whereby the external power source supplies power to power supply circuitry of power source 1308. As another example, power source 1308 can comprise a power supply unit in the form of a battery or battery pack coupled to, or integrated in, power supply circuitry. If the external power source fails, the battery can provide ready power.

[0176] Embodiments of network node 1300 can include additional components not shown in FIG. 13 that serve the same, a similar, or a different purpose. Figure 13Additional components, not shown, can be used in addition to the components shown to provide certain aspects of the functionality of the network node, including any functionality described herein and / or any functionality necessary for supporting the subject matter described herein. For example, network node 1300 can include user interface equipment to allow input of information into network node 1300 and to allow output of information from network node 1300. This can allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1300.

[0177] Figure 14 is a block diagram of a host 1400 that can be a host 1116 according to aspects described herein. As used herein, host 1400 can be or include various combinations of hardware and / or software, including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, a container, or a processing resource in a server farm. Host 1400 can provide one or more services to one or more UEs. Figure 11

[0178] Host 1400 includes processing circuitry 1402 that is operably coupled to input / output interface 1406, network interface 1408, power supply 1410, and memory 1412 via bus 1404. Other components can be included in other embodiments. Features of these components can be substantially as described with respect to the devices of previous figures, such as network node 1300, so that their description generally applies analogously to corresponding components of host 1400. Figure 12 and Figure 13

[0179] ​​The memory 1412 can include one or more computer programs, including one or more host applications 1414 and data 1416, which can include user data, e.g., data generated by the UE for the host 1400 or data generated by the host 1400 for the UE. Embodiments of the host 1400 can utilize only a subset of the illustrated components or all of them. The host applications 1414 can be implemented in a container-based architecture and can provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), MPEG, VP9) and audio codecs (e.g., FLAC, Advanced Audio Coding (AAC), MPEG, and G.711), including transcoding for multiple different classes, types, or implementations of UEs (e.g., cellphones, desktop computers, wearable display systems, heads-up display systems). The host applications 1414 can also provide user authentication and permission checks and can periodically report health, routing, and content availability to a central node, such as a device in the core network or on the edge. Thus, the host 1400 can select and / or indicate different hosts for over-the-top services for the UE. The host applications 1414 can support various protocols, such as the HTTP Live Streaming (HLS) protocol, the Real-Time Messaging Protocol (RTMP), the Real-Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (MPEG-DASH), and the like.

[0180] While the computing devices described herein (e.g., UEs, network nodes, hosts) can include combinations of the hardware components illustrated, other embodiments can include computing devices with different combinations of components. It will be appreciated that these computing devices can include any suitable combination of hardware and / or software necessary to perform the tasks, features, functions, and methods disclosed herein. Moreover, while components are depicted as single boxes or nested within multiple boxes, in practice, the computing devices can include multiple different physical components that make up a single illustrated component, and the functionality can be divided among separate components. For example, a communication interface can be configured to include any of the components described herein, and / or the functionality of the components can be divided between the processing circuitry and the communication interface. In another example, non-computationally intensive functionality of any such components can be implemented in software or firmware and computationally intensive functionality can be implemented in hardware.

[0181] In certain embodiments, some or all of the functionality described herein can be provided by a processing circuit executing instructions stored in a memory, which in certain embodiments can be a computer program product in the form of a non-transitory computer readable storage medium. In alternative embodiments, some or all of the functionality can be provided by a processing circuit without executing instructions that are stored on a separate or discrete device readable medium, such as in a hard-wired manner. In any of these particular embodiments, whether executing instructions stored on a non-transitory computer readable storage medium or not, the processing circuit can be configured to perform the described functionality. The benefits provided by such functionality can extend to other components of the computing device, but as a whole are enjoyed by the computing device and / or generally by end users and wireless networks.

[0182] REFERENCES

[0183] [1] 3GPP TS 38.211 v 17.4.0

[0184] [2] 3GPP TS 38.331 v 17.4.0

[0185] [3] 3GPP TS 38.321 v 17.4.0

Claims

1. A method performed by a user equipment, UE, (1200) in a wireless communication network, wherein, The UE is configured with two timing advance groups, TAGs, and is configured with a first control resource set, CORESET, associated with a first CORESET pool index and a second CORESET associated with a second CORESET pool index, the method comprising: receiving (902) a first random access channel, RACH, configuration (802) associated with a first physical cell identity, PCI, for contention-free random access, CFRA, wherein the first PCI is associated with the first CORESET; receiving (904) one or more second RACH configurations (804) associated with one or more respective second PCIs for CFRA, wherein the one or more second PCIs are associated with the second CORESET; receiving (906) an indication (806) of an activated second PCI of the one or more second PCIs and a request for CFRA associated with the activated second PCI; and performing (908) CFRA according to one of the one or more second RACH configurations associated with the activated second PCI.

2. The method of claim 1, wherein, The first CORESET and the second CORESET are associated with first and second transmission and reception points, TRPs, respectively.

3. The method of claim 1 or 2, wherein, The indication and the request are carried in a physical downlink control channel, PDCCH.

4. The method of any one of claims 1 to 3, wherein, The first CORESET pool index and the second CORESET pool index are different.

5. The method of any one of claims 1 to 4, wherein, Each of the one or more second RACH configurations includes a root sequence for generating a random access preamble for performing the random access, the method further comprising using the root sequence of a corresponding one of the second RACH configurations when performing the CFRA according to the activated PCI.

6. The method of any one of claims 1 to 5, wherein, Each of the one or more second RACH configurations further includes information of a respective second PCI value and information of a RACH occasion.

7. The method of any one of claims 1 to 6, wherein, Each of the one or more second RACH configurations further includes information of a common RACH parameter.

8. The method of any one of claims 1 to 7, wherein, The one or more second RACH configurations are provided as part of a dedicated RACH configuration.

9. The method of any one of claims 1 to 8, wherein, The one or more second RACH configurations are provided as part of a common RACH configuration associated with a group of cells associated with the second CORESET pool index.

10. The method of any one of claims 1 to 9, wherein, The one or more second RACH configurations are received as part of a beam failure recovery configuration.

11. The method of any one of claims 1 to 10, wherein, The UE is configured with a TA timer, and wherein upon expiry of the TA timer, the UE applies the second RACH configuration.

12. The method of any one of claims 1 to 11, wherein, The one or more second RACH configurations include respective physical random access channel, PRACH, group sequences.

13. A method performed by a user equipment, UE (1200), in a wireless communication network, comprising: receiving (912) a first random access channel, RACH, configuration (812) for contention-free random access, CFRA, to a first physical cell identity, PCI, the first PCI being associated with a first control resource set, CORESET, the first CORESET being associated with a first CORESET pool index; and performing (914) CFRA to a second PCI using the first RACH configuration for multi-transmission reception point, TRP, operation.

14. The method of claim 13, further comprising: receiving a root sequence for generating a random access preamble for performing the random access to the activated second PCI, wherein applying the RACH configuration comprises applying the RACH configuration using the root sequence when performing the CFRA to the activated second PCI.

15. The method of claim 14, wherein, The root sequence is configured by a prach-RootSequenceIndex information element.

16. The method of claim 13, further comprising: receiving a respective root sequence for each of a plurality of additional PCIs, and applying the RACH configuration using the respective root sequence when performing CFRA to one of the additional PCIs.

17. The method of claim 16, wherein, The plurality of additional PCIs comprises up to seven additional PCIs.

18. The method of any one of claims 13 to 17, wherein, The first CORESET is associated with a first TRP.

19. The method of any one of claims 13 to 18, wherein, The second PCI is associated with a second CORESET, the second CORESET being associated with a second CORESET pool index.

20. A method performed by a network node (1300) in a wireless communication network, comprising: configuring (1002) a user equipment, UE (1200), a first random access channel, RACH, configuration (802) for contention-free random access, CFRA, to a first physical cell identity, PCI, the first PCI being associated with a first control resource set, CORESET, the first CORESET being associated with a first CORESET pool index; and configuring (1004) the UE a plurality of second RACH configurations (804) for a respective second plurality of PCIs associated with a second CORESET for multi-transmission reception point, TRP, operation, the second CORESET being associated with a second CORESET pool index.

21. The method of claim 20, wherein, The first and second CORESETs are associated with a first and second TRP, respectively.

22. The method of claim 20 or 21, further comprising: configuring the UE a plurality of respective second RACH configurations associated with respective PCIs associated with the second CORESET, wherein the UE applies a respective second RACH configuration when performing CFRA to a respective PCI associated with the second CORESET.

23. The method of any one of claims 20-22, wherein, The second RACH configuration includes a root sequence for generating a random access preamble for performing the random access with the second PCI associated with the second CORESET, wherein the UE applies the RACH configuration using the root sequence when performing the CFRA with the second PCI associated with the second CORESET.

24. The method of any one of claims 20-23, wherein, The second RACH configuration is provided as part of a dedicated RACH configuration.

25. The method of any one of claims 20-24, wherein, The second RACH configuration is provided as part of a common RACH configuration associated with a cell group associated with the second CORESET.

26. The method of any one of claims 20-25, wherein, The second RACH configuration is provided as part of a beam failure recovery configuration.

27. A method performed by a network node (1300) in a wireless communication network, comprising: configuring (1012) a user equipment, UE (1200), a first random access channel, RACH, configuration (812) for contention-free random access, CFRA, to a first physical cell identifier, PCI, associated with a first control resource set, CORESET, associated with a first CORESET pool index; and configuring (1014) the UE a configuration for a second PCI associated with a second CORESET for multi-transmission reception point, TRP, operation; wherein the UE applies the RACH configuration when performing CFRA to the second PCI for multi-TRP operation.

28. The method of claim 27, further comprising: configuring the UE a root sequence for generating a random access preamble for performing the random access with the second PCI, wherein applying the RACH configuration includes using the root sequence to apply the RACH configuration when performing the CFRA to the second PCI.

29. The method of claim 27 or 28, further comprising: configuring the UE a configuration for a plurality of additional PCIs, wherein the UE applies the RACH configuration when performing CFRA to any one of the plurality of additional PCIs.

30. The method of claim 29, further comprising: configuring the UE a respective root sequence for each of the plurality of additional PCIs, wherein the UE applies the RACH configuration by using the respective root sequence to apply the RACH configuration when performing the CFRA to each of the respective PCIs.

31. A user equipment, UE (1200), comprising processing circuitry (1202) and a network interface (1212), the processing circuitry (1202) configured to perform the method of any of claims 1-19.

32. A network node (1300) comprising processing circuitry (1302) and a network interface (1306), the processing circuitry (1302) configured to perform the method of any of claims 20-30.

33. A computer program product comprising a computer readable storage medium on which is stored computer-executable instructions that, when executed by a computer, perform any of the methods of any of claims 1-30.

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