Additional random access channel (RACH) resource indexing

Abstract

A method, network node and user equipment (UE) for additional random access channel RACH resource indexing are disclosed. According to one aspect, a method in a UE includes receiving a configuration of frequency domain multiplexing for random access channel (RACH) occasions (ROs), in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs. The method includes when the sum of the number of baseline ROs and the number of additional ROs is not more than a predetermined number, then assigning a frequency index to an additional RO by adding an index of the additional RO to the baseline number. The method also includes, after assignment of a frequency index to at least one additional RO, obtaining a random access radio network temporary identifier (RA-RNTI) value based at least in part on the at least one assigned frequency index.

Description

[0001] ADDITIONAL RANDOM ACCESS CHANNEL (RACH) RESOURCE INDEXING

[0002] FIELD

[0003] The present disclosure relates to wireless communications, and in particular, to additional random access channel (RACH) resource indexing in an wireless communication network.

[0004] BACKGROUND

[0005] The Third Generation Partnership Project (3GPP) has developed and is developing standards for Fourth Generation (4G) (also referred to as Long Term Evolution (LTE)) and Fifth Generation (5G) (also referred to as New Radio (NR)) wireless communication systems. Such systems provide, among other features, broadband communication between network nodes, such as base stations, and mobile user equipments (UE), as well as communication between network nodes and between UEs. The 3GPP is also developing standards for Sixth Generation (6G) wireless communication networks.

[0006] Network node energy consumption

[0007] Network node power consumption in NR has increased significantly compared to LTE, partly due to higher bandwidth (BW) and the massive number of antennas typically employed to provide and support service. This is still evident even if there are no UEs present in a cell. Although there is no uplink (UL) or downlink (DL) transmission between a specific UE and a gNB (NR network node) in idle mode, the network node, e.g., gNB, still needs to periodically transmit signals, such as synchronization signal block (SSB) and broadcast system information, e.g., SIB1. For example, SSBs may be configured with 20ms periodicity. SIB1 may be configured with 160ms periodicity. In addition, the network node, e.g., gNB, also needs to periodically monitor the preambles from a UE to cope with random access, which implies that the receiver components of the gNB need to be turned on periodically, e.g., every 10ms or less. Hence, although increasing the sleep time of the network node, e.g., gNB, may reduce the network (network node) energy consumption, the sleep time of the network node, e.g., gNB, is constrained by the periodicity of transmit and receive.

[0008] RACH Configuration

[0009] The RACH in 5G is a fundamental uplink channel used by UE to establish communication with the gNB. It is part of the Random- Access Procedure, which enablesinitial access, connection re-establishment, handovers, and other scenarios where the UE needs to synchronize with the network or request resources. RACH resources are configured via higher layers (e.g., system information) and typical RACH resources may occur periodically as shown in the example of FIG. 1, where each cell corresponds to a slot or a subframe. After sending a RACH, the UE monitors for a RACH response in a search space (e.g., ra-searchSpace, that is configured by higher layers), and if it does not receive a response within a pre-determined amount of time, the UE tries to send RACH again.

[0010] RA-RNTI

[0011] The radio access radio network temporary identifier (RA-RNTI) associated with the PRACH occasion in which the Random Access Preamble is transmitted or the RA-RNTI associated with the last valid physical random access channel (PRACH) occasion in the set of PRACH occasions (as specified in 3GPP Technical Standard (TS) 38.213) for Msgl repetition, is computed as:

[0012] RA — RNTI = 1 + s_id + 14 x f_id + 14 x 80 x t_id + 14 x 80 x 8 x ul_carrier_id where s_id is the index of the first orthogonal frequency division multiplexed (OFDM) symbol of the PRACH occasion (0 < s_id < 14), t_id is the index of the first slot of the PRACH occasion in a system frame (0 < t_id < 80). The subcarrier spacing to determine t_id is based on the value of p specified in clause 5.3.2 in 3GPP Technical Standard (TS) 38.211 [8] for p = {0, 1, 2, 3}, and for p = {5, 6}, t_id is the index of the 120 kHz slot in a system frame that contains the PRACH occasion (0 < t_id < 80), f id is the index of the PRACH occasion in the frequency domain (0 < f id < 8), and ul carrier id is the UL carrier used for Random Access Preamble transmission (0 for a normal uplink (NUL) carrier, and 1 for supplemental uplink (SUL) carrier). The range of all RNTI may be found, for example, in 3GPP TS 38.321 V18.1.0 - 7.1, as shown in the example of FIG.

[0013] 2.

[0014] Legacy RACH occasions

[0015] Up until 3GPP Technical Release 18 (3GPP Rel-18) versions of the 3GPP specification (see, e.g., 3GPP TS 38.331 V18.0.0), PRACH resources semi-statically configured in SIB1 may be updated in by the network node via the System Information (SI) Update procedure. If the RACH configuration information in the SIB1 changes, an SI update will be signaled via the paging downlink control information (DCI) short message mechanism, in all paging occasions (POs) for the current cell during an SI modification period to ensure the information is received by all UEs camping on the cell.The actual change takes place after the SI modification period.

[0016] Additional RACH occasions

[0017] A 3GPP Rel-19 Network Energy Saving (NES) Work Item (WI) introduces dynamic adaptation of RACH occasions. As such, additional random access occasions (ROs) will be provided beyond a baseline RO configuration. This is exemplified in the examples of FIGS. 3-5, wherein a baseline configuration is provided in SIB1 according to a legacy arrangement (FIG. 3). Additional ROs are also configured in SIB1 (FIG. 4) but only intended to be used when indicated by the network node. FIG. 5 shows the sum of available ROs for the UE where the additional ROs are also activated.

[0018] In RAN1_117, RAN1_119 and RAN1_12O, the following have been considered with respect to PRACH adaptation:

[0019] Item

[0020] For adaptation of PRACH in the time domain, support at least the following case(s):

[0021] • Case 1: no time-domain overlap between the additional PRACH resources for NES-capable UEs and the PRACH resources for legacy UEs;

[0022] • Case 2: time-domain overlap but no overlap in frequency domain between the additional PRACH resources for NES-capable UEs and the PRACH resources for legacy UEs;

[0023] • Case 3: additional PRACH resources for NES-capable UEs and legacy PRACH resources overlap neither in time nor frequency domains;

[0024] • For future study (FFS): whether additional conditions are needed to support the above cases;

[0025] • FFS: Additional case whether full / partial overlap in both time and frequency is allowed; and

[0026] • Above does not preclude discussion for the case where the configuration for additional PRACH resources contains legacy PRACH resources.

[0027] Item

[0028] At least msgl-FrequencyStart may be configured separately for the additional PRACH resources at least for 4-step RACH.

[0029] Agreement

[0030] Separate configuration of Msgl-FDM (frequency division multiplex) for the additional PRACH resources at least for 4-step RACH is supported:

[0031] o UE is not expected to be configured such that there are more than 8FDM-ed valid ROs (legacy + additional ROs): and

[0032] o For further study: When there is no configuration of Msgl-FDM. A separate configuration of number of SSB per RO is supported.

[0033] If there is overlapping between the additional PRACH resources for NES-capable UEs and the PRACH resources for legacy UEs in the time domain but no overlap in the frequency domain as shown in FIG. 6, there may be an RA-RNTI ambiguity issue if legacy UE utilizes legacy RO 0 and NES-capable UE utilizes additional RO 0. This is because when the UE calculates RA-RNTI using the equation above, all parameters for that equation between the legacy UE and NES-capable UE may be same. In such cases there is contention between legacy UE and NES-capable UE, which may impact the RACH latency of legacy UE since the RACH configuration for the legacy UE may be sparse.

[0034] SUMMARY

[0035] Some embodiments advantageously provide methods, UEs and network nodes for additional RACH resource indexing.

[0036] To solve the RA-RNTI ambiguity between the legacy UE and NES-capable UE, example methods are disclosed to rearrange the index of the specified PRACH in the frequency domain. The ROs of legacy and additional ROs are indexed together when there are overlaps between legacy and additional ROs. Due to the agreement from RAN1_12O that there are no more than 8 FDM-ed valid ROs (legacy + additional ROs), the range of the calculated RA-RNTI values using a new index doesn't change from current 3 GPP specifications. Therefore, the network node doesn't need to assign more RNTI values for RA-RNTI from the RNTI pools shared with other types of RNTIs.

[0037] Some embodiments effectively avoid the RA-RNTI ambiguity issue between NES-capable UEs and the first type of UEs when there is overlapping between RO of the first and second set of RACH resources. As used herein, "overlap" refers to two ROs overlapping on both the first OFDM symbol and the first slot index of the ROs.

[0038] The range of the calculated RA-RNTI values using this method doesn't change from current 3 GPP specifications. Therefore, the network node doesn't need to assign more RNTI values for RA-RNTI from the RNTI pools shared with other types of RNTIs.

[0039] According to one aspect, a method in a user equipment, UE, configured to communicate with a network node is provided. The method includes receiving aconfiguration of frequency domain multiplexing for random access channels, RACH, occasions, ROs, in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs. The method also includes, when the sum of the number of baseline ROs and the number of additional ROs is not more than a predetermined number, then assigning a frequency index to an additional RO by adding an index of the additional RO to the baseline number. The method further includes, after assignment of a frequency index to at least one additional RO, obtaining a random access radio network temporary identifier, RA-RNTI, value based at least in part on the at least one assigned frequency index.

[0040] According to this aspect, in some embodiments, the method includes, when the sum of the baseline number of ROs and the number of additional ROs is greater than the predetermined number and the UE is configured as a network energy saving, NES, UE, then deactivating at least one of the additional ROs. In some embodiments, the method includes, when the sum of the baseline number of ROs and the number of additional ROs is greater than the predetermined number and the UE is configured as a network energy saving, NES, UE, then deactivating at least one RO of the number of baseline ROs. In some embodiments, the method includes, when the sum of the baseline number of ROs and the number of additional ROs is not more than the predetermined number, then assign a frequency index to every RO of the number of additional ROs. In some embodiments, the method includes, when the sum of the baseline number of ROs and the number of additional ROs is not more than the predetermined number, then assign a frequency index only to additional ROs that overlap an RO of the baseline number of ROs. In some embodiments, the baseline number is established based on a telecommunications standard and the number of additional ROs is configured by the network node. In some embodiments, the indices of the additional ROs start at an index equal to zero and increase uniformly. In some embodiments, the frequency indices assigned to the additional ROs start at the baseline number and increase uniformly.

[0041] According to another aspect, a user equipment, UE, configured to communicate with a network node is provided. The UE includes processing circuitry configured to receive a configuration of frequency domain multiplexing for random access channels, RACH, occasions, ROs, in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs. The processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, then assign a frequency index to anadditional RO by adding an index of the additional RO to the baseline number. In some embodiments, the processing circuitry is configured to, after assignment of a frequency index to at least one additional RO, obtain a random access radio network temporary identifier, RA-RNTI, value based at least in part on the at least one assigned frequency index.

[0042] According to this aspect, in some embodiments, the processing circuitry is configured to, when the sum of the baseline number of ROs and the number of additional ROs is greater than the predetermined number and the UE is configured as a network energy saving, NES, UE, deactivate at least one of the additional ROs. In some embodiments, the processing circuitry is configured to, when the sum of the baseline number of ROs and the number of additional ROs is greater than the predetermined number and the UE is configured as a network energy saving, NES, UE, deactivate at least one RO of the number of baseline ROs. In some embodiments, the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number , assign a frequency index to every RO of the number of additional ROs. In some embodiments, the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number , assign a frequency index only to additional ROs that overlap an RO of the baseline number of ROs. In some embodiments, the baseline number is established based on a telecommunications standard and the number of additional ROs is configured by the network node. In some embodiments, the indices of the additional ROs start at an index equal to zero and increase uniformly. In some embodiments, the frequency indices assigned to the additional ROs start at the baseline number and increase uniformly.

[0043] According to yet another aspect, a method in a network node configured to communicate with a UE is provided. The method includes providing a configuration of frequency domain multiplexing for random access channels, RACH, occasions, ROs, in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs. The method also includes, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number , then assigning a frequency index to an additional RO by adding an index of the additional RO to a maximum index of the baseline ROs. The method further includes, after assignment of a frequency index to at least one additional RO, obtaining a randomaccess radio network temporary identifier, RA-RNTI, value based at least in part on the at least one assigned frequency index.

[0044] According to this aspect, in some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE is configured as a network energy saving, NES, UE, then deactivating at least one of the additional ROs. In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE is configured as a network energy saving, NES, UE, then deactivating at least one RO of the number of baseline ROs. In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number , then assigning a frequency index to every RO of the number of additional ROs. In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number , then assigning a frequency index only to additional ROs that overlap an RO of the baseline ROs.

[0045] According to another aspect, a network node configured to communicate with a UE is provided. The network node includes processing circuitry configured to provide a configuration of frequency domain multiplexing for random access channels, RACH, occasions, ROs, in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs. The processing circuitry is also configured to, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number , then assign a frequency index to an additional RO by adding an index of the additional RO to a maximum index of the baseline ROs. In some embodiments, the processing circuitry is configured to, after assignment of a frequency index to at least one additional RO, obtain a random access radio network temporary identifier, RA-RNTI, calculation based at least in part on the at least one assigned frequency index.

[0046] According to this aspect, in some embodiments, the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE is configured as a network energy saving, NES, UE, deactivate at least one of the additional ROs. In some embodiments, the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE is configured as a network energy saving, NES, UE, deactivate at least one ROof the baseline ROs. In some embodiments, the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number , then assign a frequency index to every RO of the number of additional ROs. In some embodiments, the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number , assign a frequency index only to additional ROs that overlap an RO of the baseline ROs.

[0047] BRIEF DESCRIPTION OF THE DRAWINGS

[0048] A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

[0049] FIG. 1 illustrates uplink resources for random access;

[0050] FIG. 2 is a table of indices for RNTI;

[0051] FIG. 3 illustrates baseline configurations provided in SIB1;

[0052] FIG. 4 illustrates additional RO configurations;

[0053] FIG. 5 illustrates another configuration of ROs;

[0054] FIG. 6 illustrates time domain overlap between PRACH resources for NES-capable and legacy UEs;

[0055] FIG. 7 is a schematic diagram of an example network architecture illustrating a communication system according to principles disclosed herein;

[0056] FIG. 8 is a block diagram of a network node in communication with a user equipment over a wireless connection according to some embodiments of the present disclosure;

[0057] FIG. 9 is a schematic diagram of another example network architecture illustrating a communication system according to principles disclosed herein;

[0058] FIG. 10 is a flowchart of an example process in a network node for additional RACH resource indexing according to some embodiments of the present disclosure;

[0059] FIG. 11 is a flowchart of an example process in a user equipment for additional RACH resource indexing according to some embodiments of the present disclosure;

[0060] FIG. 12 is a flowchart of an example process in a network node for additional RACH resource indexing according to some embodiments of the present disclosure;FIG. 13 is a flowchart of an example process in a user equipment for additional RACH resource indexing according to some embodiments of the present disclosure;

[0061] FIG. 14 illustrates an example of index modification of additional random occasions (RO);

[0062] FIG. 15 illustrates an example of index modification for specific RO overlap; FIG. 16 illustrates an example of index modification and RO deactivation;

[0063] FIG. 17 illustrates an example of index modification for ROs of multiple RACH sets; and

[0064] FIG. 18 illustrates another example of index modification of multiple RACH sets.

[0065] DETAILED DESCRIPTION

[0066] Before describing in detail example embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to additional RACH resource indexing. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0067] As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0068] In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the artwill appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication.

[0069] In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and / or wireless connections.

[0070] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0071] The term “network node” used herein may be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multistandard radio (MSR) radio node such as MSR BS, multi-cell / multicast coordination entity (MCE), relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment. The term “radio node” used herein may be used to also denote a user equipment (UE) such as a wireless device (WD) or a radio network node.

[0072] In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The UE herein may be any type of user equipment capable of communicating with a network node or another UE over radio signals, such as a wireless device (WD). The UE may also be a radio communication device, target device, device to device (D2D) UE, machine type UE or UE capable of machine to machine communication (M2M), low-cost and / or low-complexity UE, a sensor equipped with UE, Tablet, mobile terminals, smart phone, laptop embedded equipped(LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (loT) device, or a Narrowband loT (NB-IOT) device etc.

[0073] Also, in some embodiments the generic term “radio network node” is used. It may be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell / multicast Coordination Entity (MCE), relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH).

[0074] Note that although terminology from one particular wireless system, such as, for example, 3GPP LTE and / or New Radio (NR) and / or 6G, may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. It is contemplated that other 3GPP systems may make use of the concepts and arrangements disclosed herein. For example, a disclosure relating to NR may also be implementable in a 6G system and / or an LTE system, a disclosure relating to 6G may also be implementable in a NR and / or LTE system, and a disclosure relating to LTE may also be implementable in a NR and / or 6G system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure.

[0075] Note further, that functions described herein as being performed by a user equipment or a network node may be distributed over a plurality of user equipments and / or network nodes. In other words, it is contemplated that the functions of the network node and user equipment described herein are not limited to performance by a single physical device and, in fact, may be distributed among several physical devices.

[0076] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0077] Some embodiments are directed to additional RACH resource indexing in wireless communication networks. Returning to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 7 a schematic diagram of acommunication system 10, according to an embodiment, such as a 3GPP-type cellular network that may support standards such as LTE and / or NR (5G) and / or 6G, which comprises an access network 12, such as a radio access network, and a core network 14. The core network 14 includes one or more network nodes 15. The access network 12 comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas 18). Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20. A first user equipment (UE) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second UE 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of UEs 22a, 22b (collectively referred to as user equipments 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding network node 16. Note that although only two UEs 22 and three network nodes 16 are shown for convenience, the communication system may include many more UEs 22 and network nodes 16.

[0078] As one example, in certain embodiments, access network 12 may contain some access network nodes 16 that support 3 GPP radio access technologies (RAT), such as LTE or NR, while other access network nodes 16 support (or the same access network nodes 16 additionally support) non-3GPP RATs, such as Wi-Fi or a proprietary RAT. As another example, communication system 10 may support multiple generations of related communication standards (e.g., 4G, 5G and 6G 3GPP communication standards) and, as a result, may include an access network 12 and / or a core network 14 that supports multiple different standard generations or may include multiple access networks 12 and / or multiple core networks 14 with individual networks supporting different standards generations.

[0079] Also, it is contemplated that a UE 22 may be in simultaneous communication and / or configured to separately communicate with more than one network node 16 and more than one type of network node 16. For example, a UE 22 may have dual connectivity with a network node 16 that supports LTE and the same or a different network node 16 that supports NR. As an example, UE 22 may be in communication with an eNB for LTE / E-UTRAN, a gNB for NR / NG-RAN (i.e., being configured for multiradio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC) and / or Wi-Fi.A network node 16 (eNB or gNB) is configured to include a NN RACH unit 24 which may be configured to determine whether an overlap occurs between a first random access channel (RACH) occasion (RO) and at least one second RO, and modify an index of the at least one second RO in a frequency domain when there is an overlap. A user equipment 22 is configured to include a UE RACH unit 26 which may be configured to determine whether an overlap occurs between a first random access channel (RACH) occasion (RO) and at least one second RO, and modify an index of the at least one second RO in a frequency domain when there is an overlap.

[0080] Example implementations, in accordance with an embodiment, of the UE 22 and network node 16 discussed in the preceding paragraphs will now be described with reference to FIG. 8.

[0081] The communication system 10 includes a network node 16 provided in a communication system 10 and including hardware 28 enabling it to communicate with the UE 22. The hardware 28 may include a communication interface 29 comprising a radio interface 30 for setting up and maintaining at least a wireless connection 32 with a UE 22 located in a coverage area 18 served by the network node 16. The radio interface 30 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and / or one or more RF transceivers. The radio interface 30 includes an array of antennas 34 to radiate and receive signal(s) carrying electromagnetic waves.

[0082] In the embodiment shown, the hardware 28 of the network node 16 further includes processing circuitry 36. The processing circuitry 36 may include a processor 38 and a memory 40. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 36 may comprise integrated circuitry for processing and / or control, e.g., one or more processors and / or processor cores and / or FPGAs (Field Programmable Gate Array) and / or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 38 may be configured to access (e.g., write to and / or read from) the memory 40, which may comprise any kind of volatile and / or nonvolatile memory, e.g., cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory).

[0083] Thus, the network node 16 further has software 42 stored internally in, for example, memory 40, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 16 via an external connection. The software 42 may be executable by the processing circuitry 36. The processing circuitry 36may be configured to control any of the methods and / or processes described herein and / or to cause such methods, and / or processes to be performed, e.g., by network node 16.

[0084] Processor 38 corresponds to one or more processors 38 for performing network node 16 functions described herein. The memory 40 is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 42 may include instructions that, when executed by the processor 38 and / or processing circuitry 36, causes the processor 38 and / or processing circuitry 36 to perform the processes described herein with respect to network node 16. For example, processing circuitry 36 of the network node 16 may include NN RACH unit 24 which may be configured to determine whether an overlap occurs between a first random access channel (RACH) occasion (RO) and at least one second RO, and modify an index of the at least one second RO in a frequency domain when there is an overlap.

[0085] The network node 16 may be composed of multiple distinct network entities (e.g., aNodeB entity and a RNC entity, or a BTS entity and a BSC entity, etc.), which may each have or utilize their own respective physical components. In certain scenarios in which the network node 16 comprises multiple such entities (e.g., BTS and BSC), one or more of the separate entities may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 16 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memories 40 or portions of memory 40 for different RATs) and some components may be reused (e.g., a same antenna may be shared by different RATs). The network node 16 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 16, for example GSM, WCDMA, LTE, NR, Wi-Fi (e.g., according to an IEEE 802.11 family standard), Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 16.

[0086] In certain alternative embodiments, network node 16 may be capable of wireless communication but does not include separate radio front-end circuitry, instead, the processing circuitry 36 includes radio front-end circuitry and is connected to the antenna 34. Similarly, in some embodiments, all or some of the RF receivers, transmitters and / or transceivers are part of the radio interface 30. In still other embodiments, thecommunication interface 29 includes one or more ports or terminals, the radio interface 30, and the RF receiver, transmitter and / or transceiver, and the communication interface 31 communicates with baseband processing circuitry, which is part of a digital unit (not shown).

[0087] The antenna 34 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 34 may be coupled to the radio front-end circuitry in radio interface 30 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 34 is separate from the network node 16 and connectable to the network node 16 through one or more interfaces or ports.

[0088] Network node 15 may include one or more components described above with respect to network node 16, e.g., communication interface 29, radio interface 30, antenna 34, ports, processing circuitry 36, processor 38, memory 40 and software 42. These elements of network node 15 may be arranged such that network node 15 may perform various core network functions. Network node 15 may communicate wirelessly or via a wired connection with network nodes 16 via communication link 59.

[0089] The communication system 10 further includes the UE 22 already referred to. The UE 22 may have hardware 44 that may include a radio interface 46 configured to set up and maintain a wireless connection 32 with a network node 16 serving a coverage area 18 in which the UE 22 is currently located. The radio interface 46 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and / or one or more RF transceivers. The radio interface 46 includes an array of antennas 48 to radiate and receive signal(s) carrying electromagnetic waves.

[0090] Communication functions of the radio interface 46 may include cellular communication, Wi-Fi communication (e.g., according to an IEEE 802.11 family standard), LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / intemet protocol (TCP / IP), synchronous optical networking (SONET),Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0091] The hardware 44 of the UE 22 further includes processing circuitry 50. The processing circuitry 50 may include a processor 52 and memory 54. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 50 may comprise integrated circuitry for processing and / or control, e.g., one or more processors and / or processor cores and / or FPGAs (Field Programmable Gate Array) and / or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 52 may be configured to access (e.g., write to and / or read from) memory 54, which may comprise any kind of volatile and / or nonvolatile memory, e.g., cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory).

[0092] Thus, the UE 22 may further comprise software 56, which is stored in, for example, memory 54 at the UE 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the UE 22. The software 56 may be executable by the processing circuitry 50. The software 56 may include a client application 58. The client application 58 may be operable to provide a service to a human or non-human user via the UE 22.

[0093] The processing circuitry 50 may be configured to control any of the methods and / or processes described herein and / or to cause such methods, and / or processes to be performed, e.g., by UE 22. The processor 52 corresponds to one or more processors 52 for performing UE 22 functions described herein. The UE 22 includes memory 54 that is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 56 and / or the client application 58 may include instructions that, when executed by the processor 52 and / or processing circuitry 50, causes the processor 52 and / or processing circuitry 50 to perform the processes described herein with respect to UE 22. For example, the processing circuitry 50 of the user equipment 22 may include a UE RACH unit 26 which may be configured to determine whether an overlap occurs between a first random access channel (RACH) occasion (RO) and at least one second RO, and modify an index of the at least one second RO in a frequency domain when there is an overlap.

[0094] In some embodiments, the inner workings of the network node 16 and UE 22 may be as shown in FIG. 8 and independently, the surrounding network topology may be thatof FIG. 7.

[0095] The wireless connection 32 between the UE 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. More precisely, the teachings of some of these embodiments may improve the data rate, latency, and / or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc. In some embodiments, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve.

[0096] Although FIGS. 7 and 8 show various “units” such as NN RACH unit 24 and UE RACH unit 26 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry.

[0097] FIG. 9 is another example of a communication system 10 according to some embodiments. As used herein, the communication system 10 of FIG. 9 includes multiple access points (APs) 60 (with four example APs 60a, 60b, 60c, and 60d being depicted) and multiple wireless devices, referred to in the context of communication system 10 of FIG. 9 as stations (STAs) 62 (referred to individually as STA 62a, STA 62b, STA 62c, STA 62d, and STA 62e). STA 62a is served by AP 60a in a first basic service set (BSS) 64a. STA 62b and STA 62c are served by AP 60b in a second BSS, BSS 64b. STA 62d is served by AP 60c in a third BSS, BSS 64c. STA 62e is served by AP 60d in a fourth BSS, BSS 64d. Stations 62 may be non-AP STAs and correspond to various kinds of wireless devices, for example, user terminals, such as mobile or stationary computing devices like smartphones, laptop computers, desktop computers, tablet computers, gaming devices, head-mounted displays (HMDs) for Augmented Reality (AR) or Virtual Reality (VR), or the like, including UEs 22 that are shown and described with respect to FIGS. 7 and 8. In other words, in some embodiment, STA 62 is a UE 22. Further, stations 62 may, for example, correspond to other kinds of equipment like smart home devices, printers, multimedia devices, data storage devices, or the like.

[0098] Each of STAs 62 may connect through a radio link to one of APs 60. For example, depending on location or channel conditions experienced by a given STA 62, the STA may select an appropriate AP and BSS for establishing the radio link. The radio link may be based on one or more orthogonal frequency-division multiplexing (OFDM) carriersfrom a frequency spectrum that is shared on the basis of a contention-based mechanism, e.g., an unlicensed or license exempt band like 2.4 GHz Industrial, Scientific, and Medical (ISM) band, the 5 GHz band, the 6 GHz band, or the 60 GHz band.

[0099] Each AP 60 may provide data connectivity to STAs 62 connected to a particular AP 60. As illustrated, APs 60 may be connected to a data network 66. In this way, APs 60 may also provide data connectivity between STAs 62 and other entities, e.g., to one or more servers, service providers, data sources, data sinks, user terminals, or the like.

[0100] Accordingly, the radio link established between a given STA 62 and its serving AP 60 may be used for providing various kinds of services to STA 62, e.g., a voice service, a multimedia service, or other data service. Such services may be based on applications that are executed on STA 62 and / or on a device linked to STA 62. By way of example, FIG. 3 illustrates an application service platform 68 provided in data network 66. The application(s) executed on STA 62 and / or on one or more other devices linked to STA 62 may use the radio link for data communication with one or more other STA 62 and / or the application service platform 68, thereby enabling utilization of the corresponding service(s) at STA 62.

[0101] FIG. 10 is a flowchart of an example process in a network node 16 for additional RACH resource indexing. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 36 (including the NN RACH unit 24), processor 38, and / or radio interface 30. Network node 16 such as via processing circuitry 36 and / or processor 38 and / or radio interface 30 is configured to determine whether an overlap occurs between a first random access channel (RACH) occasion (RO) and at least one second RO (Block S10). The process also includes modifying an index of the at least one second RO in a frequency domain when there is an overlap (Block SI 2).

[0102] In some embodiments, the index is modified only when there is a separate configuration of Msgl-FDM for the at least one RO. In some embodiments, the index is modified only when one plus the number of the at least one second RO is no more than 8. In some embodiments, modifying the index before a random access radio network temporary identifier (RA-RNTI) calculation. In some embodiments, after index modification, when the at least one second RO has a frequency division multiplex (FDM) index is greater than 8, then deactivating the first RO. In some embodiments, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the at least one second RO is configured with a Msgl-FDM configuration of the first RO. In someembodiments, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the Msgl-FDM configuration for the at least one second RO is equal to a predefined value.

[0103] FIG. 11 is a flowchart of an example process in a user equipment 22 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of user equipment 22 such as by one or more of processing circuitry 50 (including the UE RACH unit 26), processor 52, and / or radio interface 46. User equipment 22 such as via processing circuitry 50 and / or processor 52 and / or radio interface 46 is configured to determine whether an overlap occurs between a first random access channel (RACH) occasion (RO) and at least one second RO (Block SI 4). The process includes modifying an index of the at least one second RO in a frequency domain when there is an overlap (Block SI 6).

[0104] In some embodiments, the index is modified only when there is a separate configuration of Msgl-FDM for the at least one RO. In some embodiments, the index is modified only when one plus the number of the at least one second RO is no more than 8. In some embodiments, modifying the index before a random access radio network temporary identifier (RA-RNTI) calculation. In some embodiments, the UE 22 is a network energy saving (NES)-capable UE 22. In some embodiments, after index modification, when the at least one second RO has a frequency division multiplex (FDM) index is greater than 8, then deactivating the first RO. In some embodiments, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the at least one second RO is configured with a Msgl-FDM configuration of the first RO. In some embodiments, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the Msgl-FDM configuration for the at least one second RO is equal to a predefined value.

[0105] FIG. 12 is a flowchart of an example process in a network node 16 for additional RACH resource indexing. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 36 (including the NN RACH unit 24), processor 38, and / or radio interface 30. Network node 16 such as via processing circuitry 36 and / or processor 38 and / or radio interface 30 is configured to includes provide a configuration of frequency domain multiplexing for random access channels, RACH, occasions, ROs, in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs (Block SI 8). The method also includes, when the sum of the number of baseline ROs andthe number of additional ROs is not more than a predetermined number, then assigning a frequency index to an additional RO by adding an index of the additional RO to a maximum index of the baseline ROs(Block S20). The method further includes, after assignment of a frequency index to at least one additional RO, obtaining a random access radio network temporary identifier, RA-RNTI, value based at least in part on the at least one assigned frequency index (Block S22).

[0106] In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE 22 is configured as a network energy saving, NES, UE 22, then deactivating at least one of the additional ROs. In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE 22 is configured as a network energy saving, NES, UE 22, then deactivating at least one RO of the number of baseline ROs. In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, then assigning a frequency index to every RO of the number of additional ROs. In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, then assigning a frequency index only to additional ROs that overlap an RO of the baseline ROs.

[0107] FIG. 13 is a flowchart of an example process in a user equipment 22 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of user equipment 22 such as by one or more of processing circuitry 50 (including the UE RACH unit 26), processor 52, and / or radio interface 46. User equipment 22 such as via processing circuitry 50 and / or processor 52 and / or radio interface 46 is configured to receive a configuration of frequency domain multiplexing for random access channels, RACH, occasions, ROs, in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs (Block S24). The method also includes when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number , then assigning a frequency index to an additional RO by adding an index of the additional RO to a maximum index of the baseline ROs (Block S26). The method further includes after assignment of a frequency index to at least one additional RO, obtaining a random access radio network temporary identifier, RA-RNTI, value based at least in part on the at least one assigned frequency index (Block S28).In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE 22 is configured as a network energy saving, NES, UE 22, then deactivating at least one of the additional ROs. In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE 22 is configured as a network energy saving, NES, UE 22, then deactivating at least one RO of the number of baseline ROs. In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, then assign a frequency index to every RO of the number of additional ROs. In some embodiments, the method includes, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, then assign a frequency index only to additional ROs that overlap an RO of the baseline ROs. In some embodiments, the number of baseline ROs is established based on a telecommunications standard and the number of additional ROs is configured by the network node. In some embodiments, the indices of the additional ROs start at an index equal to zero and increase uniformly. In some embodiments, the frequency indices assigned to the additional ROs start at the maximum index and increase uniformly.

[0108] Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for additional RACH resource indexing.

[0109] Due to current specifications, if there are 2 ROs overlapped in the time domain, the RA-RNTI corresponding to these 2 ROs are the same. When UEs 22 search for a random access response (RAR) after having transmitted a physical random access channel (PRACH) preamble, it is possible that aNES-capable UE 22 decodes a RA-RNTI scrambled physical downlink control channel (PDCCH) in a Type 1 control search space (CSS) set successfully. This may occur although the PDCCH is intended for another UE 22 such as a legacy UE 22, and vice versa. This may confuse UEs 22, e.g., a UE 22 may detect multiple PDCCHs corresponding to its RA-RNTI in the RAR window. In one case, the UE 22 may not find the random access preamble identifier (RAPID), matching its preamble in the wrong RAR resource and recognize a failure in the current RACH attempt. However, its own PDCCH schedules a matching RAPID. In another case, the UE 22 finds a matching RAPID addressed by a wrong PDCCH and continues to proceed RARsteps although its RACH attempt has failed already at the first contention of preambles with other UEs 22.

[0110] In some embodiments, if there is separate configuration of Msgl-FDM for additional RACH and the total FDM (legacy + additional ROs) is no more than 8, both network node 16 and NES-capable UEs 22 modify the index of the additional RO in the frequency domain before RA-RNTI calculation, as shown in the example of FIG. 14 In some embodiments, only the index of the specific additional RO which overlaps with a legacy RO in the frequency domain is changed, as shown in the example of FIG. 15.

[0111] In some embodiments, if there is separate configuration of Msgl-FDM for additional RACH and the total FDM (legacy + additional ROs) is more than 8, both network node 16 and NES-capable UEs 22 modify the index of the additional RO in the frequency domain before RA-RNTI calculation. The additional ROs which have a frequency division multiplex (FDM) index more than 8 after rearranging the index together with legacy ROs are deactivated from NES-capable UE side, as shown in the example of FIG. 16.

[0112] In some embodiments, if there is no separate configuration of Msgl-FDM for an additional RACH, in one example, the additional RACH is supposed to have the same Msgl-FDM configuration with legacy, as shown in the example of FIG. 17.

[0113] In another example, additional RACH is supposed to have Msgl-FDM configuration equals to a predefined value M, as shown in the example of FIG. 18, where M=l.

[0114] Some embodiments may include one or more of the following:

[0115] 1. A network node 16 provides a configuration regarding a first set of RACH resources to the first type of UEs 22 which are not NES-capable UEs 22, and a configuration regarding a second set of RACH resources to the second type of UE 22. The second type of UE 22 is an NES-capable UE 22, and all or a part of RACH occasion (RO) of the second set of RACH resources overlaps with all or a part of the RACH occasion (RO) of first set of RACH resources (overlaps on both the first OFDM symbol and the first slot index of ROs) in the time domain but not in the frequency domain, the method comprising:

[0116] A. When there is a separate configuration of Msgl-FDM for additional RACH:

[0117] a. If the total FDM (legacy + additional ROs) is no more than 8, both network node 16 and NES-capable UEs 22 modify the index of the additional RO inthe frequency domain before RA-RNTI calculation, by:

[0118] I. Changing all indexes of the specific additional RO in the frequency domain, e.g., the frequency index of additional RO starts firomN; or II. Only changing the index of the specific additional RO which overlaps with a legacy RO in the frequency domain, e.g., the frequency index of the above additional RO starts from N;

[0119] b. If the total FDM (legacy + additional ROs) is more than 8, both network node 16 and NES-capable UEs 22 modify the index of the additional RO in the frequency domain before RA-RNTI calculation, as follows:

[0120] I. The additional ROs which have FDM index more than 8 after rearranging the index together with legacy ROs are deactivated from NES-capable UE side; and / or

[0121] II. NES-capable UE 22 only use the additional ROs B. When there is no separate configuration of Msgl-FDM for an additional RACH:

[0122] c. The additional RACH should have the same Msgl-FDM configuration with the legacy arrangement, and both network node 16 and NES-capable UEs 22 modify the index of the additional RO in the frequency domain before RA-RNTI calculation and follow the rules in 1; and / or

[0123] d. The additional RACH should have an Msgl-FDM configuration equal to a integer number M, and both network node 16 and NES-capable UEs 22 modify the index of the additional RO in the frequency domain before RA-RNTI calculation and follow the rules in 1.

[0124] Some embodiments may include one or more of the following:

[0125] Embodiment Al. A user equipment (UE) configured to communicate with a network node, the UE configured to, and / or comprising a radio interface and / or processing circuitry configured to:

[0126] determine whether an overlap occurs between a first random access channel (RACH) occasion (RO) and at least one second RO; and

[0127] modify an index of the at least one second RO in a frequency domain when there is an overlap.

[0128] Embodiment A2. The UE of Embodiment Al, wherein the index is modified only when there is a separate configuration of Msgl-FDM for the at least one RO.Embodiment A3. The UE of Embodiment A2, wherein the index is modified only when one plus the number of the at least one second RO is no more than 8.

[0129] Embodiment A4. The UE of any of Embodiments Al -A3, wherein modifying the index before a random access radio network temporary identifier (RA-RNTI) calculation.

[0130] Embodiment A5. The UE of any of Embodiments A1-A4, wherein the UE is a network energy saving (NES)-capable UE.

[0131] Embodiment A6. The UE of any of Embodiments A1-A5, wherein, after index modification, when the at least one second RO has a frequency division multiplex (FDM) index is greater than 8, then deactivating the first RO.

[0132] Embodiment A7. The UE of any of Embodiments A1-A5, wherein, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the at least one second RO is configured with a Msgl-FDM configuration of the first RO.

[0133] Embodiment A8. The UE of any of Embodiments A1-A5, wherein, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the Msgl-FDM configuration for the at least one second RO is equal to a predefined value.

[0134] Embodiment Bl. A method implemented in a user equipment (UE) that is configured to communicate with a network node, the method comprising:

[0135] determining whether an overlap occurs between a first random access channel (RACH) occasion (RO) and at least one second RO; and

[0136] modifying an index of the at least one second RO in a frequency domain when there is an overlap.

[0137] Embodiment B2. The method of Embodiment B 1 , wherein the index is modified only when there is a separate configuration of Msgl-FDM for the at least one RO.

[0138] Embodiment B3. The method of Embodiment B2, wherein the index is modified only when one plus the number of the at least one second RO is no more than 8.

[0139] Embodiment B4. The method of any of Embodiments B1-B3, wherein modifying the index before a random access radio network temporary identifier (RA-RNTI) calculation.

[0140] Embodiment B5. The method of any of Embodiments B1-B4, wherein the UE is a network energy saving (NES)-capable UE.Embodiment B6. The method of any of Embodiments B1-B5, wherein, after index modification, when the at least one second RO has a frequency division multiplex (FDM) index is greater than 8, then deactivating the first RO.

[0141] Embodiment B7. The method of any of Embodiments B1-B5, wherein, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the at least one second RO is configured with a Msgl-FDM configuration of the first RO.

[0142] Embodiment B8. The method of any of Embodiments B1-B5, wherein, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the Msgl-FDM configuration for the at least one second RO is equal to a predefined value.

[0143] Embodiment Cl. A network node configured to communicate with a user equipment (UE), the network node configured to, and / or comprising a radio interface and / or comprising processing circuitry configured to:

[0144] determine whether an overlap occurs between a first random access channel (RACH) occasion (RO) and at least one second RO; and

[0145] modify an index of the at least one second RO in a frequency domain when there is an overlap.

[0146] Embodiment C2. The network node of Embodiment C 1 , wherein the index is modified only when there is a separate configuration of Msgl-FDM for the at least one RO.

[0147] Embodiment C3. The network node of Embodiment C2, wherein the index is modified only when one plus the number of the at least one second RO is no more than 8.

[0148] Embodiment C4. The network node of any of Embodiments C1-C3, wherein modifying the index before a random access radio network temporary identifier (RA-RNTI) calculation.

[0149] Embodiment C5. The network node of any of Embodiments C1-C4, wherein, after index modification, when the at least one second RO has a frequency division multiplex (FDM) index is greater than 8, then deactivating the first RO.

[0150] Embodiment C6. The network node of any of Embodiments C1-C5, wherein, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the at least one second RO is configured with a Msgl-FDM configuration of the first RO.

[0151] Embodiment C7. The network node of any of Embodiments C1-C6, wherein, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the Msgl-FDM configuration for the at least one second RO is equal to a predefined value.Embodiment DI. A method implemented in a network node that is configured to communicate with a user equipment, the method comprising:

[0152] determining whether an overlap occurs between a first random access channel (RACH) occasion (RO) and at least one second RO; and

[0153] modifying an index of the at least one second RO in a frequency domain when there is an overlap.

[0154] Embodiment D2. The method of Embodiment D 1 , wherein the index is modified only when there is a separate configuration of Msgl-FDM for the at least one RO.

[0155] Embodiment D3. The method of Embodiment D2, wherein the index is modified only when one plus the number of the at least one second RO is no more than 8.

[0156] Embodiment D4. The method of any of Embodiments D1-D3, wherein modifying the index before a random access radio network temporary identifier (RA-RNTI) calculation.

[0157] Embodiment D5. The method of any of Embodiments D1-D5, wherein, after index modification, when the at least one second RO has a frequency division multiplex (FDM) index is greater than 8, then deactivating the first RO.

[0158] Embodiment D6. The method of any of Embodiments D1-D5, wherein, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the at least one second RO is configured with a Msgl-FDM configuration of the first RO.

[0159] Embodiment D7. The method of any of Embodiments D1-D6, wherein, when there is no separate configuration of Msgl-FDM for the at least one second RO, then the Msgl-FDM configuration for the at least one second RO is equal to a predefined value.

[0160] As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and / or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and / or functionality described herein may be performed by, and / or associated to, a corresponding module, which may be implemented in software and / or firmware and / or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that may be executed by a computer. Any suitable tangible computerreadable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices.

[0161] Some embodiments are described herein with reference to flowchart illustrations and / or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, may be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0162] These computer program instructions may also be stored in a computer readable memory or storage medium that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function / act specified in the flowchart and / or block diagram block or blocks.

[0163] The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0164] It is to be understood that the functions / acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality / acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.

[0165] Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Python, Java®or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0166] Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments may be combined in any way and / or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination.

[0167] Abbreviations that may be used in the preceding description include:

[0168] Abbreviation Explanation

[0169] NES Network Energy Saving PRACH Physical Random-Access Channel RACH Random Access Channel RAR Random Access Response RA-RNTI Random Access Radio Network Temporary Identifier RO RACH Occasion

[0170] UE User Equipment

[0171] It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

What is claimed is:

1. A method in a user equipment, UE (22), configured to communicate with a network node (16), the method comprising:receiving (S24) a configuration of frequency domain multiplexing for random access channels, RACH, occasions, ROs, in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs;when a sum of the number of baseline ROs and the number of additional ROs is not more than a predetermined number (S26), then assigning a frequency index to an additional RO by adding an index of the additional RO to a maximum index of the baseline ROs; andafter assignment of a frequency index to at least one additional RO (S28), obtaining a random access radio network temporary identifier, RA-RNTI, value based at least in part on the at least one assigned frequency index.

2. The method of Claim 1, further comprising, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE (22) is configured as a network energy saving, NES, UE (22), then deactivating at least one of the additional ROs.

3. The method of any of Claims 1 and 2, further comprising, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE (22) is configured as a network energy saving, NES, UE (22), then deactivating at least one RO of the number of baseline ROs.

4. The method of any of Claims 1-3, further comprising, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, then assign a frequency index to every RO of the number of additional ROs.

5. The method of any of Claims 1-3, further comprising, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, then assign a frequency index only to additional ROs that overlap an RO of the baseline ROs.

6. The method of any of Claims 1-5, wherein the number of baseline ROs is established based on a telecommunications standard and the number of additional ROs is configured by the network node (16).

7. The method of any of Claims 1-6, wherein the indices of the additional ROs start at an index equal to zero and increase uniformly.

8. The method of Claim 7, wherein the frequency indices assigned to the additional ROs start at the maximum index and increase uniformly.

9. A user equipment, UE (22), configured to communicate with a network node (16), the UE (22) comprising processing circuitry configured to:receive a configuration of frequency domain multiplexing for random access channels, RACH, occasions, ROs, in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs;when the sum of the number of baseline ROs and the number of additional ROs is not more than a predetermined number, then assign a frequency index to an additional RO by adding an index of the additional RO to a maximum index of the baseline ROs; and after assignment of a frequency index to at least one additional RO, obtain a random access radio network temporary identifier, RA-RNTI, value based at least in part on the at least one assigned frequency index.

10. The UE (22) of Claim 9, wherein the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE (22) is configured as a network energy saving, NES, UE (22), deactivate at least one of the additional ROs.

11. The UE (22) of any of Claims 9 and 10, wherein the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE (22) is configured as a network energy saving, NES, UE (22), deactivate at least one RO of the baseline ROs.

12. The UE (22) of any of Claims 9-11, wherein the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, assign a frequency index to every RO of the additional ROs.

13. The UE (22) of any of Claims 9-11, wherein the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, assign a frequency index only to additional ROs that overlap an RO of the baseline ROs.

14. The UE (22) of any of Claims 9-13, wherein the number of baseline ROs is established based on a telecommunications standard and the number of additional ROs is configured by the network node (16).

15. The UE (22) of any of Claims 9-114, wherein the indices of the additional ROs start at an index equal to zero and increase uniformly.

16. The UE (22) of Claim 15, wherein the frequency indices assigned to the additional ROs start at the maximum index number and increase uniformly.

17. A method in a network node (16) configured to communicate with a UE (22), the method comprising:providing (SI 8) a configuration of frequency domain multiplexing for random access channels, RACH, occasions, ROs, in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs;when the sum of the number of baseline ROs and the number of additional ROs is not more than a predetermined number (S20), then assigning a frequency index to an additional RO by adding an index of the additional RO to a maximum index of the baseline ROs; andafter assignment of a frequency index to at least one additional RO (S22), obtaining a random access radio network temporary identifier, RA-RNTI, value based at least in part on the at least one assigned frequency index.

18. The method of Claim 17, further comprising, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE (22) is configured as a network energy saving, NES, UE (22), then deactivating at least one of the additional ROs.

19. The method of any of Claims 17 and 18, further comprising, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE (22) is configured as a network energy saving, NES, UE (22), then deactivating at least one RO of the number of baseline ROs.

20. The method of any of Claims 17-19, further comprising, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, then assigning a frequency index to every RO of the number of additional ROs.

21. The method of any of Claims 17-19, further comprising, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, then assigning a frequency index only to additional ROs that overlap an RO of the baseline ROs.

22. A network node (16) configured to communicate with a UE (22), the network node (16) comprising processing circuitry configured to:provide a configuration of frequency domain multiplexing for random access channels, RACH, occasions, ROs, in addition to baseline ROs, the configuration including a number of the baseline ROs and a number of the additional ROs;when the sum of the number of baseline ROs and the number of additional ROs is not more than a predetermined number, then assign a frequency index to an additional RO by adding an index of the additional RO to a maximum index of the baseline ROs; and after assignment of a frequency index to at least one additional RO, obtain a random access radio network temporary identifier, RA-RNTI, value based at least in part on the at least one assigned frequency index.

23. The network node (16) of Claim 22, wherein the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additionalROs is greater than the predetermined number and the UE (22) is configured as a network energy saving, NES, UE (22), deactivate at least one of the additional ROs.

24. The network node (16) of any of Claims 22 and 23, wherein the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is greater than the predetermined number and the UE (22) is configured as a network energy saving, NES, UE (22), deactivate at least one RO of the baseline ROs.

25. The network node (16) of any of Claims 22-24, wherein the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, then assign a frequency index to every RO of the additional ROs.

26. The network node (16) of any of Claims 22-25, wherein the processing circuitry is configured to, when the sum of the number of baseline ROs and the number of additional ROs is not more than the predetermined number, assign a frequency index only to additional ROs that overlap an RO of the baseline ROs.

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