Patent Publication Number: US-2022225407-A1

Title: Methods, ue and network node for handling a bandwidth part configuration

Description:
TECHNICAL FIELD 
     The present disclosure generally relates to telecommunications and embodiments herein relate to a User Equipment (UE), a method performed by the UE, a network node and a method performed by the network node. In particular, the various embodiments described in this disclosure relate to apparatuses and methods for handling bandwidth configurations. 
     BACKGROUND 
     Next generation, such as New Radio (NR), systems are expected to support a wide range of use cases with varying requirements ranging from fully mobile devices to stationary Internet of Things (IoT) devices or fixed wireless broadband devices. The traffic pattern associated with many use cases is expected to comprise short or long bursts of data traffic with varying length of waiting period in between, here called inactive state. In NR, both license assisted access and standalone operation in NR-Unlicensed spectrum (NR-U) are to be supported in Third Generation Partnership Project (3GPP). Hence, the procedure of Physical Random Access CHannel (PRACH) transmission and/or Scheduling Request (SR) transmission in unlicensed spectrum shall be investigated in 3GPP. 
     With network operation in unlicensed spectrum follows a number of restrictions. One of them is that a device, e.g. a radio network node or a UE, has to monitor the shared medium, i.e. the channel, and determine that it is free, i.e. not being used by any other device, before starting to transmit on the channel. This procedure is referred to as Listen-Before-Talk (LBT) or Clear Channel Assessment (CCA). The procedure is also referred to as Listen Before Transmit. 
     In the following, NR-U and channel access procedure for an unlicensed channel based on LBT is introduced. 
     NR-U Introduction 
     In order to tackle the ever-increasing data demand, NR is considered for both licensed and unlicensed spectrum. Compared to Long Term Evolution (LTE) Licensed Assisted Access (LAA), NR-U also needs to support Dual Connectivity (DC) and standalone scenarios, where the Medium Access Control (MAC) procedures comprising Random Access CHannel (RACH) and scheduling procedure on unlicensed spectrum are subject to LBT and thus, potential LBT failures. In LTE LAA, there are no such issues since the RACH and scheduling related signaling may be transmitted on the Primary Cell (PCell) in licensed spectrum instead of unlicensed spectrum. 
     For Discovery Reference Signal (DRS) transmission such as Primary Synchronization Signal/Secondary Synchronization Signal (PSS/SSS), Physical Broadcast Channel (PBCH), Channel State Information-Reference Signal (CSI-RS), control channel transmission such as Physical Uplink Control Channel/Physical Downlink Control Channel (PUCCH/PDCCH), such as Physical Uplink Shared Channel/Physical Downlink Shared Channel (PUSCH/PDSCH), and uplink Sounding Reference Signal (SRS) such as SRS transmission, channel sensing should be applied to determine the channel availability before the physical signal is transmitted using the channel. 
     The Radio Resource Management (RRM) procedures in NR-U would be generally rather similar to those in LAA, since NR-U is aiming to reuse LAA/eLAA/feLAA technologies as much as possible to handle the coexistence between NR-U and other legacy Radio Access Technologies (RATs). RRM measurements and report comprising special configuration procedure with respect the channel sensing and channel availability. 
     Hence, channel access/selection for LAA was one of the important aspects for co-existence with other RATs such as Wi-Fi. For instance, LAA has aimed to use carriers that are congested with Wi-Fi. 
     Channel Access Procedure in NR-U 
     Listen-before-talk (LBT) is designed for unlicensed spectrum co-existence with other RATs. In this mechanism, a radio device applies a Clear Channel Assessment (CCA) check, i.e. channel sensing, before any transmission. The transmitter involves Energy Detection (ED) over a time period compared to a certain energy detection threshold, e.g. ED threshold, in order to determine if a channel is idle. In case the channel is determined to be occupied, the transmitter performs a random back-off within a contention window before next CCA attempt. In order to protect the Acknowledgement (ACK) transmissions, the transmitter must defer a period after each busy CCA slot prior to resuming back-off. As soon as the transmitter has grasped access to a channel, the transmitter is only allowed to perform transmission up to a maximum time duration, namely, the Maximum Channel Occupancy Time (MCOT). For Quality of Service (QoS) differentiation, a channel access priority based on the service type has been defined. For example, four LBT priority classes are defined for differentiation of channel access priorities between services using different Contention Window Sizes (CWS) and MCOT durations. 
     As described in 3GPP TR 38.889 V16.0.0 (December 2018), the channel access schemes for NR-based access for unlicensed spectrum may be classified into at least some of the following categories (cat): 
     Cat-1: Immediate transmission after a short switching gap
         This is used for a transmitter to immediately transmit after an Uplink/Downlink (UL/DL) switching gap inside a COT.   The switching gap from reception to transmission is to accommodate the transceiver turnaround time and is no longer than 16 μs.       

     Cat-2: LBT without random back-off
         The duration of time that the channel is sensed to be idle before the transmitting entity transmits is deterministic.       

     Cat-3: LBT with random back-off with a contention window of fixed size
         The LBT procedure has the following procedure as one of its components. The transmitting entity draws a random number N within a contention window. The size of the contention window is specified by the minimum and maximum value of N. The size of the contention window is fixed. The random number N is used in the LBT procedure to determine the duration of time that the channel is sensed to be idle before the transmitting entity transmits on the channel.       

     Cat-4: LBT with random back-off with a contention window of variable size
         The LBT procedure has the following as one of its components. The transmitting entity draws a random number N within a contention window. The size of contention window is specified by the minimum and maximum value of N. The transmitting entity may vary the size of the contention window when drawing the random number N. The random number N is used in the LBT procedure to determine the duration of time that the channel is sensed to be idle before the transmitting entity transmits on the channel.       

     For different transmissions in a COT and different channels/signals to be transmitted, different categories of channel access schemes may be used. 
     RACH Procedures in NR Unlicensed Spectrum 
     The ordinary four-step Random Access (RA) has been the current standard for legacy systems such as LTE and NR Rel-15. It has been proposed to study a two-step procedure where the UL messages, e.g. PRACH and/or Msg3, are sent simultaneously and similarly the two DL messages, e.g. time advance command in RAR and contention resolution information, are sent as a simultaneous response in the DL. In the legacy four step procedure, one purpose of the first two messages is to obtain UL time alignment for the UE. In many situations, e.g. in small cells or for stationary UEs, this may not be needed since either a TA=0 will be sufficient (small cells) or a stored TA value from the last RA may serve also for the current RA (stationary UE). TA is short for Timing Advance and is a parameter. TA may be described as a negative offset used by the UE and is the time between the start of a received downlink sub frame and a transmitted uplink sub frame. In future radio networks it may be expected that these situations are common, due to both dense deployments of small cells and a great number of stationary devices, e.g. stationary IoT devices. A possibility to skip the message exchange in cases there is no need to obtain the TA value would lead to reduced RA latency and would be beneficial in several use cases, for example when transmitting infrequent small data packets. On the other hand, the two step RA will consume more resources since it uses contention-based transmission of the data. This means that the resources that are configured for the data transmission may often be unused. 
     If both the 4-step and 2-step RA are configured in a cell, and for the UE, the UE will choose its preamble from one specific set if it wants to do a 4-step RA, and from another set if it wants to do a 2-step RA. Hence, a preamble partition is done to distinguish between 4-step and 2-step RA. Alternatively, the PRACH configurations are different for the 2-step and 4-step RA procedure, in which case it may be deduced from where the preamble transmission is done if the UE is doing a 2-step or 4-step procedure. 
     Legacy 4-Step Random Access 
     The legacy 4-step RA has been used in LTE and is also proposed as baseline for NR. The principle of this procedure is shown in  FIG. 1 . The network node  101  illustrated in  FIG. 1  may be e.g. a eNB, gNB, NB, or any other radio access node or access node or other suitable node. 
     Step 1: Preamble Transmission 
     The UE  103  randomly selects a RA preamble, e.g. PREAMBLE_INDEX, which is then transmitted by the UE  103  to the network node  101 . When the network node  101  detects the preamble, it estimates the TA the UE  103  should use in order to obtain UL synchronization at the network node  101 . 
     Step 2: RA Response (RAR) 
     The network node  101  sends a RA Response (RAR) comprising the TA, the Temporary Cell-Radio Network Temporary Identifier (TC-RNTI) to be used by the UE  103 , a Random Access Preamble identifier that matches the transmitted PREAMBLE_INDEX and a grant for Msg3. The UE  103  expects the RAR and thus, monitors PDCCH addressed to RA-RNTI to receive the RAR message from the network node  101  until the configured RAR window, e.g. a ra-ResponseWindow parameter, has expired or until the RAR has been successfully received. 
     From 3GPP TS 38.321 V15.5.0 (March 2019): “The MAC entity may stop ra-ResponseWindow (and hence monitoring for Random Access Response(s)) after successful reception of a Random Access Response containing Random Access Preamble identifiers that matches the transmitted PREAMBLE_INDEX”. 
     Step 3: Msg3—UE ID or UE-Specific C-RNTI 
     In Message 3 (Msg3) the UE  103  transmits its identifier, e.g. UE ID, for initial access or—if it is already in RRC_CONNECTED or RRC_INACTIVE mode and e.g. needs to resync, its UE-specific RNTI. If the network node  101  may not decode Msg3 at the granted UL resources, it may send Downlink Control Information (DCI) addressed to TC-RNTI for retransmission of Msg3. HARQ retransmission is requested until the UEs  103  restart the random access procedure from step 1 after reaching the maximum number of Hybrid Automatic Repeat reQuest (HARQ) retransmissions or until Msg3 may be successfully received by the network node  101 . 
     Step 4: Msg4—Contention Resolution 
     In Message 4 (Msg4), the network node  101  responds by acknowledging the UE ID or C-RNTI. The Msg4 gives contention resolution, i.e. only one UE ID or C-RNTI may be sent even if several UEs have used the same preamble, and the same grant for Msg3 transmission, simultaneously. 
     For Msg4 reception, the UE  103  monitors TC-RNTI, if it transmitted its UE ID in Msg3, or C-RNTI, if it transmitted its C-RNTI in Msg3. 
     In LTE, the 4-step RA may not be completed in less than 14 ms/TTI/SF. TTI is short for Time Transmission Interval and SF is short for Sub Frame. 
     2-Step Random Access 
     The 2-step RA gives much shorter latency than the ordinary 4-step RA. In the 2-step RA, the preamble and a message corresponding to Msg3 in the 4-step RA are transmitted in the same or in two subsequent sub frames. The Msg3 is sent on a resource dedicated to the specific preamble. This means that both the preamble and the Msg3 face contention, but contention resolution in this case means that either both preamble and Msg3 are sent without collision or both collide. The 2-step RA procedure is depicted in  FIG. 2 . The method exemplified in  FIG. 2  comprises at least one of the following steps, which steps may be performed in any suitable order than described below: 
     Step  201 : The UE  103  sends a RA preamble to the network node  101 . The network node  101  receives the RA preamble from the UE  103 . 
     Step  202 : The UE  103  sends Msg3 to the network node  101 . Msg3 may comprise a C-RNTI/ID. The network node  101  receives Msg3 from the UE  103 . 
     Step  201  and  202  may be done in the same sub frame, i.e. the messages in steps  201  and  202  may be sent in the same sub frame. 
     Step  203 : The network node  101  sends a RA response to the UE  103 . The RA response may comprise TA. The UE  103  receives the RA response from the network node  101 . 
     Step  204 : The network node  101  sends Msg4 to the UE  103 . Msg4 may comprise content resolution information. The UE  103  receives Msg4 from the network node  101 . 
     Step  203  and  204  may be done in the same sub frame, i.e. the messages in steps  203  and  204  may be sent in the same sub frame. 
     Upon successful reception of the preamble and Msg3, the network node  101  may respond with a TA, which by assumption should not be needed or just give very minor updates, and an Msg4 for contention resolution. 
     An issue that may occur if the UE TA is bad, e.g. using TA=0 in a large cell or using an old TA even though the UE  103  has moved, is that only the preamble may be detected by the network node  101 . This may be because a transmission with an inaccurate TA value may interfere with transmissions from other UEs in the same cell. Additionally, the preamble signal has higher detection probability than the normal data due to its design pattern. In this case, the network node  101  may reply with an ordinary RAR giving the UE  103  an opportunity to transmit an ordinary Msg3 on a scheduled resource. This is a fallback to 4-step RA. 
     Wideband Operation in NR-U 
     As in NR licensed, it is expected that NR-U may support transmission over a wide bandwidth (&gt;&gt;20 MHz). It is expected that this may be achieved in two different ways: (1) carrier aggregation with configuration of multiple serving cells, e.g., each with 20 MHz bandwidth, and (2) configuration of a single wideband serving cell with bandwidth as an integer multiple of 20 MHz, e.g. 80 MHz. 
     The following objective is listed in the NR-U WID: 
     Wide band operation, in integer multiples of 20 MHz, for DL and UL for NR-U supported with multiple serving cells, and wideband operation, in integer multiples of 20 MHz, for DL and UL for NR-U supported with one serving cell with bandwidth &gt;20 MHz with potential scheduling constraints on feasibility of operating the wideband carrier when LBT is unsuccessful in one or more LBT sub bands within the wideband carrier. For all wideband operation cases, CCA is performed in units of 20 MHz, at least for 5 GHz. A LBT sub band may also be referred to as a frequency sub band or subcarrier band. 
     In both scenarios, CCA is performed in units of 20 MHz, at least for 5 GHz. Two modes according to relationship between the Carrier BandWidth (CBW) and the LBT BandWidth (LBW) may be defined:
         Mode 1   Mode 2       

     In Mode 1, multiple carriers are aggregated, and for each carrier the relationship is that CBW=LBT. For Mode 2, a single wideband carrier is used and the relationship is CBW&gt;LBW. In Wideband Mode 2, the wideband carrier therefore comprises multiple LBT sub bands or multiple LBT bandwidths. 
     This terminology may be applied generically for both the 5 and 6 GHz bands. For the 5 GHz band, LBW=20 MHz. However, for the 6 GHz band, the LBW is still under discussions. It may be possible that the basic channelization is based on a larger unit than 20 MHz, e.g., 80 MHz, in which case the LBW would be 80 MHz as well. 
     SUMMARY 
     It is in view of the above background and other considerations that the various embodiments of the present disclosure have been made. 
     Band-Width Parts (BWP) 
     For NR, 3GPP has standardized the use of Band Width Parts (BWPs). The reasons for using BWPs are that some UEs might not be able to use the entire BW, in which case they are assigned a smaller BWP which they are capable of handling. Another reason is for battery savings. A UE may be assigned a more narrow BWP to reduce the needed energy for reception and transmission. Yet another reason may be for load balancing when the UEs does not need the entire BW to meet the bit rate requirements. 
     According to 3GPP TS 38.211 V15.5.0 (March 2019), section 4.4.5, a carrier bandwidth part is defined as follows: “Carrier Bandwidth Part is a contiguous set of physical resource blocks, selected from a contiguous subset of the common resource blocks for a given numerology(u) on a given carrier.” 
     It has been agreed that each UE is assigned with at least an initial BWP, the same for all UEs, narrow enough for all UEs to handle, and a default BWP. The default BWP may be the same as the initial BWP but may also be different, i.e. different UEs may have different default BWPs. In addition to initial and default BWP, the UE may be configured with additional BWPs. It has been agreed that a UE may have up to four DL/UL BWPs. An important agreement is also that at any point in time, only one BWP is active for a specific UE. 
     A BWP may also be configured with PRACH occasions, allowing the UE to initiate a Random Access procedure on the BWP. The configuration of PRACH occasions on a BWP is not mandatory except on the initial BWP, where it is always present to allow initial access. Also for PUCCH a BWP may or may not have PUCCH resources configured. The reason for not having a PUCCH configured is that it occupies resources which may lead to overhead, especially in configured but not active BWPs. When a UE  103  initiates a Random Access procedure, it must first ensure that the active BWP contains PRACH occasions and that the DL BWP has the same BWP-ID as the active UL BWP. This is specified in 3GPP TS 38.321 V15.5.0 (March 2019) in Section 5.15. 
     An example of a possible BWP and PRACH configuration on a wide carrier with 20 MHz LBT-sub bands according to legacy is shown in  FIG. 3 . 
     In  FIG. 3 , three BWPs are shown: an initial BWP  301 , a first non-initial BWP  303  and second non-initial BWP  305 . The initial BWP  301  has PRACH resources and may be used for initial access. Both the overlapping BWP 1   303  and BWP 2   305  have PRACH resources in the overlapping sub band. The overlapping may be seen by the overlapping bracket in  FIG. 3 . This may be used in connected mode if the UE  103  has either BWP 1  or BWP 2  as active BWP.  FIG. 3  also shows the wideband carrier, which comprises the initial BWP  301 , the first non-initial BWP  303  and the second non-initial BWP  305 . The LBT sub band may of a size of 20 MHz. 
     With support of multiple LBT sub-bands within a BWP, benefits of providing additional transmission opportunities for an NR-U UE to mitigate the negative impact imposed by LBT operations may be achieved. 
     One question may be how to provide PRACH configuration across different LBT sub-bands within a BWP. In the NR Rel-15, the time domain locations for PRACH resources are configured by the parameter prach-ConfigurationIndex while the frequency domain locations for RA preambles are configured by the parameter msg1-FrequencyStart and the parameter msg1-FDM. The three parameters are carried by the RRC IE RACH-ConfigGeneric, which is further carried by the IE RACH-ConfigCommon in the IE BWP-UplinkCommon. In this way, the PRACH resources are configured per BWP. So, the existing PRACH configuration framework is not sufficient to support multiple LBT sub-bands. 
     Therefore, there is a need to at least mitigate or solve these issues. 
     An objective of embodiments herein is therefore to obviate at least one of the above disadvantages and to improve handling of BWPs. Another objective may be to improve handling of RA procedures. 
     These general objects have been addressed by the appended independent claims. Advantageous embodiments are defined in the appended dependent claims. 
     According to a first aspect, there is provided a method performed by a User Equipment (UE) in a communications system. 
     The method comprises receiving information indicating a Bandwidth Part (BWP) configuration from a network node. The BWP configuration comprises at least one initial BWP and at least one non-initial BWP. The method further comprises transmitting, to the network node, a Random Access (RA) preamble message according to the received BWP configuration to initiate a RA procedure with the network node. 
     In some embodiments, the BWP configuration comprises a primary initial BWP, at least one secondary initial BWP, and at least one non-initial BWP. The at least one secondary initial BWP may be configured via a supplementary carrier, or in a second cell which belongs to a same or a different cell group as the cell where the RA is triggered, or in the same cell as the primary initial BWP. 
     In some embodiments, at least one of said at least one initial BWP comprises a plurality of Listen-Before-Talk (LBT) sub bands. The method may then comprise selecting one of the plurality of LBT sub bands; and transmitting the RA preamble to the network node on the selected LBT sub band. 
     In some embodiments, at least one of said at least one non-initial BWP comprises a plurality of LBT sub bands. RACH occasions (ROs) may be configured across a plurality of said plurality of LBT sub bands. The ROs may belong to a same or different PRACH configuration. 
     In some embodiments, at least one of the following parameters is defined in the PRACH configuration: a first parameter indicating a sub band offset; a second parameter indicating a number of PRACH transmission occasions in one time instance in one LBT sub band; and a reused at least one existing third parameter associated with LBT sub band. The at least one parameter may be defined for every sub band or for configured specific sub bands. 
     According to a second aspect, there is provided a method performed by a network node in a communications system. 
     The method comprises determining a BWP configuration. The BWP configuration comprises at least one initial BWP and at least one non-initial BWP. The method further comprises transmitting information indicating the determined BWP configuration to a UE; and receiving a RA preamble message from the UE according to the determined BWP configuration. 
     In some embodiments, the BWP configuration comprises a primary initial BWP, at least one secondary initial BWP, and at least one non-initial BWP. The at least one secondary initial BWP may be configured via a supplementary carrier, in a second cell which belongs to a same or a different cell group as the cell where the RA is triggered, or in the same cell as the primary initial BWP. 
     In some embodiments, at least one of said at least one initial BWP comprises a plurality of LBT sub bands. The method may comprise receiving the RA preamble on a selected LBT sub band of the plurality of LBT sub bands, wherein the selected LBT sub band has been selected by the UE. 
     In some embodiments, at least one of said at least one non-initial BWP comprises a plurality of LBT sub bands. RO may be configured across a plurality of said plurality of LBT sub bands. The ROs may belong to a same or different PRACH configuration. 
     In some embodiments, at least one of the following parameters is defined in the PRACH configuration: a first parameter indicating a sub band offset; a second parameter indicating a number of PRACH transmission occasions in one time instance in one LBT sub band; and a reused at least one existing third parameter associated with LBT sub band. The at least one parameter may be defined for every sub band or for configured specific sub bands. 
     In some embodiments, a separate PRACH configuration is configured in a LBT sub band, wherein the separate PRACH configuration is associated with a LBT sub band index. 
     According to a third aspect, there is provided a UE adapted to perform the method according to the first aspect. 
     The UE is adapted to receive information indicating a BWP configuration from a network node. The BWP configuration comprises at least one initial BWP and at least one non-initial BWP. The UE is further adapted to transmit, to the network node, a RA preamble message according to the received BWP configuration to initiate a RA procedure with the network node. 
     In some embodiments, the BWP configuration comprises a primary initial BWP, at least one secondary initial BWP, and at least one non-initial BWP. The at least one secondary initial BWP may be configured via a supplementary carrier, in a second cell which belongs to a same or a different cell group as the cell where the RA is triggered; or in the same cell as the primary initial BWP. 
     In some embodiments, at least one of said at least one initial BWP comprises a plurality of LBT sub band. The UE may be adapted to select one of the plurality of LBT sub bands and to transmit the RA preamble to the network node on the selected LBT sub band. 
     In some embodiments, at least one of said at least one non-initial BWP comprises a plurality of LBT sub bands. ROs may be configured across a plurality of said plurality of LBT sub bands. The ROs may belong to a same or different PRACH configuration. 
     In some embodiments, at least one of the following parameters is defined in the PRACH configuration: a first parameter indicating a sub band offset; a second parameter indicating the number of PRACH transmission occasions in one time instance in one LBT sub band; and a reused at least one existing third parameter associated with LBT sub band. The at least one parameter may be defined for every sub band or for configured specific sub bands. 
     In some embodiments, a separate PRACH configuration is configured in a LBT sub band, wherein the separate PRACH configuration is associated with a LBT sub band index. 
     According to a fourth aspect, there is provided a network node adapted to perform the method according to the second aspect. 
     The network node is adapted to determine a BWP configuration. The BWP configuration comprises at least one initial BWP and at least one non-initial BWP. The network node is further adapted to transmit information indicating the determined BWP configuration to the UE; and to receive a RA preamble message from the UE according to the determined BWP configuration. 
     In some embodiments, the configuration for BWP comprises a primary initial BWP, at least one secondary initial BWP, and at least one non-initial BWP. The at least one secondary initial BWP may be configured via a supplementary carrier, in a second cell which belongs to a same or a different cell group as the cell where the RA is triggered, or in the same cell as the primary initial BWP. 
     In some embodiments, at least one of said at least one initial BWP comprises a plurality of LBT sub bands. The network node may be adapted to receive the RA preamble on a selected LBT sub band of the plurality of LBT sub bands. The selected LBT sub band has been selected by the UE. 
     In some embodiments, at least one of said at least one non-initial BWP comprises a plurality of LBT sub bands. ROs may be configured across a plurality of said plurality of LBT sub bands. The ROs may belong to a same or different PRACH configuration. 
     In some embodiments, at least one of the following parameters is defined in the PRACH configuration: a first parameter indicating a sub band offset; a second parameter indicating the number of PRACH transmission occasions in one time instance in one LBT sub band; and a reused at least one existing third parameter associated with LBT sub band. The at least one parameter may be defined for every sub band or for configured specific sub bands. 
     In some embodiments, a separate PRACH configuration is configured in a LBT sub band. 
     The separate PRACH configuration is associated with a LBT sub band index. 
     According to a fifth aspect, there is provided a computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to the first and/or second aspect. 
     According to a sixth aspect, there is provided a carrier comprising the computer program of the fifth aspect, wherein the carrier is one of an electronic signal, optical signal, radio signal or computer readable storage medium. 
     The various proposed embodiments herein provide an improved handling of BWPs and of RA procedures. Embodiments herein afford many advantages, of which a non-exhaustive list of examples are that they enable reduction of random access latency and that unnecessary transmissions are minimized 
     The embodiments herein are not limited to the features and advantages mentioned above. A person skilled in the art will recognize additional features and advantages upon reading the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments herein will now be further described in more detail by way of example only in the following detailed description by reference to the appended drawings illustrating the embodiments and in which: 
         FIG. 1  is a flow chart illustrating an example of a 4-Step RACH procedure. 
         FIG. 2  is a flow chart illustrating an example of a 2-step RA procedure. 
         FIG. 3  is an example illustration of a possible BWP and PRACH configuration on a wide carrier with 20 MHz LBT-sub bands according to legacy methods. 
         FIG. 4  is a schematic block diagram illustrating an example of a communications system. 
         FIG. 5  is a signaling diagram illustrating an example of a method. 
         FIG. 6  is a flow chart according to embodiments herein. 
         FIG. 7  is a flow chart according to embodiments herein. 
         FIG. 8  is an example illustration of two initial BWPs. 
         FIG. 9  is an example illustration of PRACH overlapping two sub-bands in the same initial BWP. 
         FIG. 10  is an example illustration of use of new msg1-FDM-sub band parameter and re-interpretation of msg1-FrequencyStart, sub band offset in  FIG. 8 . 
         FIG. 11 a -11 b    are schematic drawings illustrating an example of a UE. 
         FIG. 12 a -12 b    are schematic drawings illustrating an example of a network node. 
         FIG. 13  is a schematic block diagram illustrating a telecommunication network connected via an intermediate network to a host computer. 
         FIG. 14  is a schematic block diagram of a host computer communicating via a base station with a UE over a partially wireless connection. 
         FIG. 15  is a flowchart depicting embodiments of a method in a communications system comprising a host computer, a base station and a UE. 
         FIG. 16  is a comprising depicting embodiments of a method in a communications system comprising a host computer, a base station and a UE. 
         FIG. 17  is a flowchart depicting embodiments of a method in a communications system comprising a host computer, a base station and a UE. 
         FIG. 18  is a flowchart depicting embodiments of a method in a communications system comprising a host computer, a base station and a UE. 
     
    
    
     The drawings are not necessarily to scale and the dimensions of certain features may have been exaggerated for the sake of clarity. Emphasis is instead placed upon illustrating the principle of the embodiments herein. 
     DETAILED DESCRIPTION 
     The embodiments herein relate to configuration of Physical Random Access CHannel (PRACH) resources across different Listen-Before-Talk (LBT) sub-bands. The embodiments also relate to methods for handling BandWidth configurations comprising at least one initial BandWidth Part (BWP) and at least one non-initial BWP. 
       FIG. 4  depicts a non-limiting example of a communications system  100 , which may be a wireless communications system, sometimes also referred to as a wireless communications network, cellular radio system, or cellular network, in which embodiments herein may be implemented. The communications system  100  may be a Fifth Generation (5G) system, 5G network, NR-U or Next Gen system or network. The communications system  100  may alternatively be a younger system than a 5G system. The communications system  100  may support other technologies such as, for example, Long-Term Evolution (LTE), LTE-Advanced/LTE-Advanced Pro, e.g. LTE Frequency Division Duplex (FDD), LTE Time Division Duplex (TDD), LTE Half-Duplex Frequency Division Duplex (HD-FDD), LTE operating in an unlicensed band, NB-IoT. The communications system  100  may be a 2G network, a 3G network, a 4G network, a 5G network, a 6G network or any other legacy, current or future network. Thus, although terminology from 5G/NR and LTE may be used in this disclosure to exemplify embodiments herein, this should not be seen as limiting the scope of the embodiments herein to only the aforementioned systems. 
     The communications system  100  comprises one or a plurality of network nodes, whereof the network node  101  is depicted in the non-limiting example of  FIG. 4 . The network node  101   a  may be a radio network node, such as a radio base station, or any other network node with similar features capable of serving a UE  103 , such as a wireless device or a machine type communication (MTC) device, in the communications system  100 . The network node  101  may be an eNB, gNB, MeNB, RNC, NB, etc. 
     The communications system  100  may cover a geographical area, which may be divided into cell areas, wherein each cell area may be served by a network node, although, one network node may serve one or several cells. Note that any n number of cells may be comprised in the communications system  100 , where n is any positive integer. A cell is a geographical area where radio coverage is provided by the network node  101  at a network node site. Each cell is identified by an identity within the local network node area, which is broadcast in the cell. In  FIG. 4 , network node  101  may serve a cell. The network node  101  may be of different classes, such as, e.g., macro base station (BS), home BS or pico BS, based on transmission power and thereby, also cell size. The network node  101  may be directly connected to one or more core networks, which are not depicted in  FIG. 4  for the sake of simplicity. The network node  101  may be a distributed node, such as a virtual node in the cloud, and it may perform its functions entirely on the cloud, or partially, in collaboration with another network node. 
     One or a plurality of UEs  103  is located in the communication system  100 . Only one UE  103  is exemplified in  FIG. 4  for the sake of simplicity. A UE  103  may also be referred to simply as a device. The UE  103 , e.g. a LTE UE or a 5G/NR UE, may be a wireless communication device, which may also be known as e.g., a wireless device, a mobile terminal, wireless terminal and/or mobile station, a mobile telephone, cellular telephone, or laptop with wireless capability, just to mention some further examples. The UE  103  may be a device by which a subscriber may access services offered by an operator&#39;s network and services outside operator&#39;s network to which the operator&#39;s radio access network and core network provide access, e.g. access to the Internet. The UE  103  may be any device, mobile or stationary, enabled to communicate over a radio channel in the communications network. For example, the UE  103  may be, but is not limited to, a user equipment, mobile phone, smart phone, sensors, meters, vehicles, household appliances, medical appliances, media players, cameras, Machine to Machine (M2M) device, Internet of Things (IOT) device, terminal device, communication device or any type of consumer electronic, for instance, but not limited to, television, radio, lighting arrangements, tablet computer, laptop or Personal Computer (PC). The UE  103  may be portable, pocket storable, hand held, computer comprised, or vehicle mounted devices, enabled to communicate voice and/or data, via the radio access network, with another entity. The other entity may be an entity such as another UE, a server, a laptop, a Personal Digital Assistant (PDA), or a tablet, Machine-to-Machine (M2M) device, device equipped with a wireless interface, such as a printer or a file storage device, modem, or any other radio network unit capable of communicating over a radio link in a communications system. 
     The UE  103  is enabled to communicate wirelessly within the communications system  100 . The communication may be performed e.g. between two devices, between a devices and a regular telephone, between the UE  103  and a network node, between network nodes, and/or between the devices and a server via the radio access network and possibly one or more core networks and possibly the internet. 
     The network node  101  may be configured to communicate in the communications system  100  with the UE  103  over a communication link, e.g., a radio link. 
     It should be noted that the communication links in the communications network may be of any suitable kind comprising either a wired or wireless link. The link may use any suitable protocol depending on type and level of layer (e.g. as indicated by the OSI model) as understood by the person skilled in the art. 
     When the text herein describes the network node  101  performs an action or method step, this may also be described as the network performs a certain action or method steps. In other words, the network may be represented by a network node  101  performing the action or method step described herein. 
     According to a first aspect of the present disclosure, there is provided a method performed by a UE  103  in a communications system  100 . According to a second aspect of the present disclosure, there is provided a method performed by a network node  101  in a communications system  100 . These methods are first going to be described with reference to  FIG. 5 .  FIG. 5  is a signaling diagram illustrating an example of the methods. The methods comprise at least one of the following steps, which steps may be performed in any suitable order than described below: 
     Step  501   
     The network node  101  determines a BWP configuration. This may also be described as the network node  101  configures PRACH across different LBT sub-bands. 
     Step  502   
     The network node  101  provides information indicating the BWP configuration to the UE  103 . The information may be provided by transmitting it directly to the UE  103 , or by transmitting it via some other node to the UE  103 , e.g. via another network node, memory unit etc. The information may be the actual BWP configuration or it may be an address to a node form which the UE  103  may obtain the BWP configuration. The UE  103  obtains the information indicating the PWP configuration from the network node  101 , 
     Step  503   
     The UE  103  may select a LBT sub band from multiple LBT sub bands. This step may be performed when the initial BWP comprises multiple LBT sub bands. 
     Step  504   
     The UE  103  provides a RA preamble message to the network node  101 . This may also be described as the UE  103  initiating a RA procedure. The RA preamble message may be provided to the network node  101  using the determined BWP configuration, i.e. the BWP configuration determined in step  501 . The network node  101  obtains the RA preamble message from the UE  103 . This may also be described as the network node  101  detects that the UE  103  has initiated a RA procedure. 
     The method described above will now be described seen from the perspective of the UE  103  with reference to  FIG. 6 . The method  600  performed by a UE  103  in a communications system  100  comprises at least one of the following described steps, which steps may be performed in any suitable order than described below. The method  600  may start with step  605  of obtaining information indicating a BWP configuration from the network node  101 . Step  605  in  FIG. 6  corresponds to step  502  in  FIG. 5 . The obtaining of information comprises step  610  of receiving information indicating a BWP configuration from a network node  101 . The information may be received directly from the network node  101  or via some other node or memory unit. The BWP configuration comprises at least one initial BWPs and at least one non-initial BWPs. The method  600  may further comprise step  625  of initiating a RA procedure according to the obtained BWP configuration. Step  625  in  FIG. 6  corresponds to step  504  in  FIG. 5 . The initiating of the RA procedure comprises step  630  of transmitting, to the network node  101 , a RA preamble message according to the received BWP configuration to initiate a RA procedure with the network node  101 . 
     In some embodiments, the BWP configuration may comprise a primary initial BWP, at least one secondary initial BWP, and at least one non-initial BWP. In other embodiments, the BWP configuration may comprise a primary initial BWP, a first non-initial BWP, and a second non-initial BWP. 
     In embodiments when the BWP configuration comprises at least one secondary initial BWP, the at least one secondary initial BWP may be configured, by the network node  101 , via a supplementary carrier, or in a second cell which belongs to a same cell group or a different cell group as the cell where the RA is triggered, or in the same cell as the primary initial BWP. Thus, the at least one secondary initial BWP may be configured, by the network node  101 , via a supplementary carrier. Alternatively, the at least one secondary initial BWP may be configured in a second cell which belongs to a same cell group or a different cell group as the cell where the RA is triggered. Alternatively, the at least one secondary initial BWP may be configured in the same cell as the primary initial BWP. 
     In some embodiments, the initial BWP, e.g. the primary initial BWP, may comprise a Listen-Before-Talk (LBT) sub band. In some embodiments, at least one of said at least one initial BWP, e.g. the primary initial BWP, may comprise a plurality of LBT sub bands. For example, the primary initial BWP may comprise a first LBT sub band and a second LBT sub band. In these embodiments, the method  600  performed by the UE  103  may further comprise step  620  of selecting one of the plurality of LBT sub bands. Step  620  in  FIG. 6  corresponds to step  503  in  FIG. 5 . If the primary initial BWP comprises a first and a second LBT sub bands, the UE may select the first LBT sub band or the second LBT sub band. Then, the step  630  of transmitting the RA preamble to the network node  101  comprises transmitting the RA preamble to the network node  101  on the selected LBT sub band, i.e. the selected first LBT sub band or second LBT sub band. The selected first LBT sub band or second LBT sub band may be the LBT sub band that wins the LBT. 
     In some embodiments, the at least one of said at least one non-initial BWP, e.g. the first non-initial BWP and/or the second non-initial BWP, may comprise a plurality of LBT sub bands. When the non-initial BWP comprises multiple LBT sub bands, RACH occasions, ROs, may be configured across a plurality of said plurality of LBT sub bands. The ROs may belong to a same or different PRACH configuration. 
     According to some embodiments, at least one of the following parameters may be defined in the PRACH configuration, e.g. according to RRC IE RACH-ConfigGeneric or RRC RACH-ConfigGeneric, a first parameter, a second parameter or a reused at least one third existing parameter associated with LBT sub band. The first parameter indicating a sub band offset and may be referred to as e.g. msg1-FrequencyStart-sub band. The second parameter indicating the number of PRACH transmission occasions in one time instance in one LBT sub band and may be referred to as e.g. msg1-FDM-sub band. RRC RACH-ConfigGeneric or RRC IE RACH-ConfigGeneric may be described as an information element or parameter, i.e. a generic RACH parameter. It may be used to specify the cell specific RA parameters both for regular RA as well as for beam failure recovery. The at least one parameter, e.g. the msg1-FDM-sub band parameter and/or an msg1-FrequencyStart-sub band parameter, may be defined for every sub band or for configured specific sub bands. 
     In some embodiments, a separate PRACH configuration corresponding to e.g., RRC IE RACH-ConfigCommon may be configured in a LBT sub band. The separate PRACH configuration may be associated with a LBT sub band index. RRC IE RACH-ConfigCommon may also be referred to as RRC RACH-ConfigCommon. RRC IE RACH-ConfigCommon may be described as a parameter or information element. The RACH-ConfigCommon IE is used to specify the cell specific random-access parameters. According to another aspect, the present disclosure provides a first computer program, which may comprise instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of embodiments described herein, e.g. the method  600  performed by the UE  103 . A first carrier may comprise the first computer program, and the first carrier may be one of an electronic signal, optical signal, radio signal or computer readable storage medium. 
     The method in the signalling diagram described above will now be described with reference to  FIG. 7 , seen from the perspective of the network node  101 . The method  700  performed by a network node  101  in a communications system  100  comprises at least one of the following described steps, which steps may be performed in any suitable order than described below. The method  700  starts with step  710  of determining a BWP configuration. Step  710  in  FIG. 7  corresponds to step  501  in  FIG. 5 . The BWP configuration comprises at least one initial BWP and at least one non-initial BWPs. The method  700  continues with step  715  of providing information indicating the determined BWP configuration to the UE  103 . Step  715  in  FIG. 7  corresponds to step  502  in  FIG. 5 . The step  715  of providing information indicating the determined BWP configuration to the UE  103  comprises step  720  of transmitting information indicating the determined BWP configuration to the UE  103 . The information may be transmitted directly or via some other node or memory unit. The method  700  further comprises step  730  of receiving a RA preamble message from the UE  103  according to the determined BWP configuration. Step  730  in  FIG. 7  corresponds to step  504  in  FIG. 5 . 
     In some embodiments, the BWP configuration may comprise a primary initial BWP, at least one secondary initial BWP, and at least one non-initial BWP. In other embodiments, the BWP configuration may comprise a primary initial BWP, a first non-initial BWP, and a second non-initial BWP. 
     In embodiments when the BWP configuration comprises at least one secondary initial BWP, the at least one secondary initial BWPs may be configured via a supplementary carrier; or in a second cell which belongs to a same cell group or a different cell group as the cell where the RA is triggered; or in the same cell as the primary initial BWP. 
     In some embodiments, the initial BWP, e.g. the primary initial BWP, may comprise a LBT sub band. In some embodiments, the initial BWP, e.g. the primary initial BWP, may comprise a plurality of LBT sub bands, e.g. a first LBT sub band and a second LBT sub band. In these embodiments, the method  700  performed by the network node  101  may further comprise step  730  of receiving the RA preamble on a selected LBT sub band of the plurality of LBT sub bands, wherein the LBT sub band has been selected by the UE  103 . If the initial BWP comprises a first LBT sub band and a second LBT sub band, the RA preamble may be received on the selected first or second LBT sub band, which has been selected by the UE  103 . For example, the selected LBT sub band, e.g. first LBT sub band or second LBT sub band, may be the LBT sub band that wins the LBT. The LBT sub band that wins the LBT may be the LBT sub band that fulfills a LBT criterion. 
     In some embodiments, at least one of said at least one non-initial BWP may comprise a plurality of LBT sub bands. For example, the first non-initial BWP and/or the second non-initial BWP may comprise at least one LBT sub band. In these embodiments, when the non-initial BWP comprises a plurality of LBT sub bands, ROs may be configured across a plurality of said plurality LBT sub bands. The ROs may belong to a same or different PRACH configuration. 
     In some embodiments, at least one of the following parameters may be defined in the PRACH configuration, e.g. according to RRC IE RACH-ConfigGeneric, a first parameter indicating a sub band offset, a second parameter indicating the number of PRACH transmission occasions in one time instance in one LBT sub band, and a reused at least one existing third parameter associated with LBT sub band. The first parameter may be referred to as e.g. msg1-FrequencyStart-sub band. The second parameter may be referred to as e.g. msg1-FDM-sub band. 
     The at least one parameter, e.g. the msg1-FDM-sub band parameter and/or an msg1-FrequencyStart-sub band parameter, may be defined for every sub band or for configured specific sub bands. 
     In some embodiments, a separate PRACH configuration corresponding to e.g., RRC IE RACH-Config Common, may be configured in a LBT sub band. The separate PRACH configuration may be associated with a LBT sub band index. 
     The network node  101  may be an NB, eNB, gNB, RNC, access node, RAN node, core network, CN, node, etc., or any other suitable network node. 
     According to another aspect, the present disclosure provides a second computer program, which may comprise instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of embodiments described herein, e.g. the method performed by the network node  101 . A second carrier may comprise the second computer program, and the second carrier may be one of an electronic signal, optical signal, radio signal or computer readable storage medium. 
     The below embodiments are described in the context of NR unlicensed spectrum (NR-U). The embodiments herein are not limited to NR-U scenarios. They are also applicable to other unlicensed operation scenarios such as LTE LAA/eLAA/feLAA/MulteFire. 
     In one embodiment, at least one secondary initial BWP may be defined for the UE  103  to improve transmission opportunities for Random accesses triggered for initial access. In this embodiment, the bandwidth for each initial BWP is restricted to the bandwidth of a LBT sub band, e.g., 20 MHz. Hence, it comprises one LBT sub-band. In this case, the UE  103  is configured with a primary initial BWP, plus at least one secondary BWP. Given a UE  103  configured with up to 4 BWPs, therefore, occupying BWI IDs in the range between 0 and 3. The secondary initial BWPs would then occupy BWP IDs in the range beyond 4. All initial BWPs are configured using RMSI. This is illustrated in  FIG. 8 . In  FIG. 8 , the UE  103  may do initial access on either of the two initial BWPs, if the LBT succeeds on that sub band.  FIG. 8  shows the wideband carrier as comprising the primary initial BWP, the secondary initial BWP and the first non-initial BWP. A LBT sub band may be of 20 MHz. 
     In one example embodiment, a secondary initial BWP may be configured via a supplementary carrier. For providing more FDMed RACH resources, a UE  103  may be configured at least one supplementary uplink (SUL) carriers in UL, and/or one or multiple SUL carriers in DL. 
     In another example embodiment, a secondary initial BWP may be configured in a second cell, which belong a same or a different cell group with the cell where the RA is triggered. The cell group may share the same timing advance or the same PUCCH resources, or the same set of PRACH resources. 
     In yet another example embodiment, a secondary initial BWP may be configured in the same cell as the primary initial BWP. In this case, the cell may therefore configure more than 4 BWPs for a UE  103 . 
     For a RA triggered for initial access, the UE  103  may perform multiple LBT operations in parallel, and each of them on a different initial BWP, either on a primary or on a secondary initial BWP, the UE  103  then selects just one of initial BWP, which has succeeded LBT operation, to transmit PRACH preamble. For simplicity, the UE  103  may choose to stay on the same initial BWP to complete the RA procedure. 
     The network node  101  may need to monitor all configured initial BWPs, since the network node  101  is not aware in which initial BWP a UE  103  may initiate a RA procedure. 
     In another embodiment, the initial BWP may comprise more than one LBT sub-bands, i.e., its bandwidth is not restricted to one LBT sub band. In this case, RACH occasions (ROs) may be configured across LBT sub-bands. These ROs belong to the same or different PRACH configurations. This is illustrated in  FIG. 9 , where two RACH occasions are configured in the initial BWP and the first belongs to first LBT sub band and the second to the second LBT sub band.  FIG. 9  shows the wideband carrier comprising a primary initial BWP, a first non-initial BWP and a second non-initial BWP. The LBW sub band may be 20 MHz. 
     For a RA triggered for initial access, the UE  103  may perform multiple LBT operations in parallel, and each of them on a different LBT sub band within the initial BWP, the UE  103  then selects just one of LBT sub-bands which has succeeded LBT operation, to transmit PRACH preamble. For simplicity, the UE  103  may choose to stay on the same LBT sub band to complete the RA procedure. 
     The network node  101  may need to monitor all LBT sub-bands within the initial BWP, since the network node  101  is not aware in which LBT sub band a UE  103  may initiate a RA procedure. 
     In an embodiment where a non-initial BWP comprises multiple LBT sub-bands, then RACH occasions (ROs) may be configured across LBT sub bands. These ROs belong to the same or different PRACH configurations. 
     In another embodiment, in order to configure ROs belonging to a same PRACH configuration across sub-bands in the associated BWP, besides the 3GPP parameters msg1-FrequencyStart and msg1-FDM, one or multiple additional parameters may be defined in the RRC IE RACH-ConfigGeneric. These parameters may be new parameters or existing parameters, which are reused. However, the embodiments herein are not limited by these examples, in other examples, different names of parameters may be used. 
     As an example, an additional parameter named as msg1-FDM-sub band may be introduced, which defines the number of PRACH transmission occasions FDMed in one time instance in one LBT sub band. Meanwhile, the existing parameter msg1-FrequencyStart may be redefined to indicate an Offset of lowest PRACH transmission occasion in frequency domain with respective to the first PRB within a LBT sub band. The value may be configured so that the corresponding RACH resource is entirely within the bandwidth of the UL LBT sub band. In this example, the total number of all PRACH ROs in frequency domain in all concerned LBT sub band in a BWP may equal to msg1-FDM. 
     As an example, an additional parameter named as msg1-FDM-sub band may be introduced, which defines the number of PRACH transmission occasions FDMed in one time instance in one LBT sub band. Meanwhile, another new parameter msg1-FrequencyStart-sub band is also introduced to indicate Offset of lowest PRACH transmission occasion in frequency domain with respective to the first PRB within a LBT sub band. The value may be configured so that the corresponding RACH resource is entirely within the bandwidth of the UL LBT sub band. 
     These two parameters may be defined for every sub band, or for configured specific sub-bands. In principle, a different LBT sub band may be configured with different settings of these two parameters. Therefore, in a single PRACH configuration, a list of settings may be comprised and each of them may be applicable to a different LBT sub band. This is illustrated in  FIG. 10 .  FIG. 10  illustrates use of a new msg1-FDM-sub band parameter and re-interpretation of msg1-FrequencyStart, indicated as Sub band offset in  FIG. 10 .  FIG. 10  shows a wideband carrier comprising a primary initial BWP, a first non-initial BWP and a second non-initial BWP. The LBT sub band may be for example 20 MHz. The primary initial BWP is associated with a PRACH and msg1-FrequencyStart. The first non-initial BWP is associated with a PRACH and a sub band offset, e.g. msg1-FrequencyStart-subband parameter, in a first sub band, a PRACH and a sub band offset, e.g. msg1-FrequencyStart-subband in a second sub band, a PRACH and a sub band offset in a third sub band. The second non-initial BWP is not associated with PRACH. 
     As an example, there is no new parameter defined, by setting a proper value for the parameter msg1-FrequencyStart so that PRACH transmission occasions in frequency domain in one time instance to cross at least one LBT sub band boundary. In this case, configured RO in the second LBT sub band may start from the first PRB in the second LBT sub band. As another option, configured RO in the second LBT sub band may start from a PRB with an offset with respective to the first PRB in the second LBT sub band. In this case, an additional new parameter to define the offset need to be configured accordingly. There may be one or multiple PRBs at the boundary of the first LBT sub band are not used for ROs, since they may not be sufficient to fill one PRACH RO. 
     In a further embodiment, a separate PRACH configuration corresponding to RRC IE RACH-ConfigCommon, is configured in a LBT sub band. In this case, this PRACH configuration is associated with a LBT sub band index. In RRC IE BWP-Uplink or BWP-Downlink, a list of LBT sub band indices need to be comprised. In this way, a BWP may be configured via RRC to comprise multiple LBT sub bands. 
     Note that although the methods herein are described in the context of NR, the same methods may be applied to any access technologies that make use of SI like LTE or Narrowband-Internet of Things (NB-IoT). 
       FIG. 11 a    and  FIG. 11 b    depict two different examples in panels a) and b), respectively, of the arrangement that the UE  103  may comprise. In some embodiments, the UE  103  may comprise the following arrangement depicted in  FIG. 11   a.    
     The embodiments herein in the UE  103  may be implemented through one or more processors, such as a processor  1101  in the UE  103  depicted in  FIG. 11   a,  together with computer program code for performing the functions and actions of the embodiments herein. A processor, as used herein, may be understood to be a hardware component. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the UE  103 . One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the UE  103 . 
     The UE  103  may further comprise a memory  1103  comprising one or more memory units. The memory  1103  is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the UE  103 . Thus, the UE  103  may be configured to perform the method according to the first aspect. 
     In some embodiments, the UE  103  may receive information from, e.g., the network node  101 , through a receiving port  1104 . In some embodiments, the receiving port  1104  may be, for example, connected to one or more antennas in UE  103 . In other embodiments, the UE  103  may receive information from another structure in the communications system through the receiving port  1104 . Since the receiving port  1104  may be in communication with the processor  1101 , the receiving port  1104  may then send the received information to the processor  1101 . The receiving port  1104  may also be configured to receive other information. 
     The processor  1101  in the UE  103  may be further configured to transmit or send information to e.g. first network node  101  or another structure in the communications system  100 , through a sending port  1105 , which may be in communication with the processor  1110 , and the memory  1103 . 
     The UE  103  may comprise an obtaining unit  1115 , an initiating unit  1117 , a selecting unit  1120 , a transmitting unit  1121 , and other units  1140 . 
     The UE  103  in a communications system  100  is adapted to obtain, e.g. by means of the obtaining unit  1115 , e.g. by receiving, information indicating a BWP configuration from the network node  101 . Thus, the UE  103  is adapted, or configured, to receive, e.g. by means of the obtaining unit  1115 , information indicating a BWP configuration from the network node  101 . The information may be received directly from the network node  101  or via some other node or memory unit. The BWP configuration comprises at least one initial BWP and at least one non-initial BWP. The UE  103  is further adapted, or configured, to initiate, e.g. by means of the initiating unit  1117 , a RA procedure according to the obtained BWP configuration. The UE  103  is adapted, or configured, to transmit, e.g. by means of the initiating unit  1117 , a RA preamble message to the network node  101 . 
     In some embodiments, the BWP configuration may comprise a primary initial BWP, at least one secondary initial BWP, and at least one non-initial BWP. In other embodiments, the BWP configuration may comprise a primary initial BWP, a first non-initial BWP, and a second non-initial BWP. 
     In embodiments when the BWP configuration comprises at least one primary and at least one secondary initial BWP, the at least one secondary initial BWP may be configured via a supplementary carrier; or in a second cell which belongs to a same cell group or a different cell group as the cell where the RA is triggered; or in the same cell as the primary initial BWP. 
     In some embodiments, the initial BWP, e.g. the primary initial BWP, may comprise a LBT sub band. In some embodiments, at least one of said at least one initial BWP, e.g. the primary initial BWP, may comprise a plurality of LBT sub bands. For example, the primary initial BWP may comprise a first LBT sub band and a second LBT sub band. In these embodiments, when at least one of said at least one initial BWP, e.g. the primary initial BWP, comprises a plurality of LBT sub bands, the UE  103  may be adapted to select, e.g. by means of the selecting unit  3020 , one of the plurality of LBT sub bands; and to transmit, e.g. by means of the transmitting unit  3021 , the RA preamble to the network node  101  on the selected LBT sub band. The selected sub band, e.g. the first LBT sub band or second LBT sub band, may be the LBT sub band that wins the LBT, e.g. the LBT sub band that fulfills a criterion. 
     In some embodiments at least one of said at least one non-initial BWP, e.g. the first non-initial BWP and/or the second non-initial BWP, may comprise at least one LBT sub band. In these embodiments, when the non-initial BWP comprises multiple LBT sub bands, ROs may be configured across multiple LBT sub bands, and the ROs belong to a same or different PRACH configuration. 
     In some embodiments, at least one of the following parameters may be defined in the PRACH configuration, e.g. according to RRC IE RACH-ConfigGeneric, a first parameter indicating a sub band offset, a second parameter indicating the number of PRACH transmission occasions in one time instance in one LBT sub band, and a reused at least one existing third parameter associated with LBT sub band. The first parameter may be referred to as e.g. msg1-FrequencyStart-sub band. The second parameter may be referred to as e.g. msg1-FDM-sub band. The at least one other parameter, e.g. the msg1-FDM-sub band parameter and/or an msg1-FrequencyStart-sub band parameter, may be defined for every sub band or for configured specific sub bands. 
     In some embodiments, a separate PRACH configuration corresponding to e.g., RRC IE RACH-Config Common may be configured in a LBT sub band. The separate PRACH configuration may be associated with a LBT sub band index. 
     Those skilled in the art will also appreciate that the obtaining unit  1115 , the initiating unit  1117 , the selecting unit  1120 , the transmitting unit  1121  and other units  1140  described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processor  1101 , perform as described above. One or more of these processors, as well as the other digital hardware, may be comprised in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC). 
     Also, in some embodiments, the different units  1115 - 1140  described above may be implemented as one or more applications running on one or more processors such as the processor  1101 . 
     Thus, the methods according to the embodiments described herein for the UE  103  may be respectively implemented by means of a computer program  1110  product, comprising instructions, i.e., software code portions, which, when executed on at least one processor  1101 , cause the at least one processor  1101  to carry out the actions described herein, as performed by the UE  103 . The computer program  1110  product may be stored on a computer-readable storage medium  1108 . The computer-readable storage medium  1108 , having stored thereon the computer program  1110 , may comprise instructions which, when executed on at least one processor  1101 , cause the at least one processor  1101  to carry out the actions described herein, as performed by the UE  103 . In some embodiments, the computer-readable storage medium  1108  may be a non-transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. In other embodiments, the computer program  1110  product may be stored on a carrier comprising the computer program  1110  just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium  508 , as described above. 
     The UE  103  may comprise a communication interface configured to facilitate communications between the UE  103  and other nodes or devices, e.g., the network node  101  or another structure. The interface may comprise, for example, a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard. 
     In other embodiments, the UE  103  may comprise the following arrangement depicted in  FIG. 11   b.  The UE  103  may comprise a processing circuitry  1101 , e.g., one or more processors such as the processor  1110 , in the UE  103  and the memory  1103 . The UE  103  may also comprise a radio circuitry  1113 , which may comprise e.g., the receiving port  1104  and the sending port  1105 . The processing circuitry  1111  may be configured to, or operable to, perform the method actions according to  FIG. 5 , in a similar manner as that described in relation to  FIG. 11   a.  The radio circuitry  1113  may be configured to set up and maintain at least a wireless connection with the UE  103 . Circuitry may be understood herein as a hardware component. 
     Hence, embodiments herein also relate to the UE  103  operative to operate in the communications system. The UE  103  may comprise the processing circuitry  1111  and the memory  1103 , said memory  1103  comprising instructions executable by the processing circuitry  1111 , whereby the UE  103  is further operative to perform the actions described herein in relation to the UE  103 , e.g. in  FIGS. 5 and 6 . 
       FIGS. 12 a    and  FIG. 12 b    depict two different examples in panels a) and b), respectively, of the arrangement that the network node  101  may comprise. In some embodiments, the network node  101  may comprise the following arrangement depicted in  FIG. 12   a.    
     The embodiments herein in the network node  101  may be implemented through one or more processors, such as a processor  1201  in the network node  101  depicted in  FIG. 12   a,  together with computer program code for performing the functions and actions of the embodiments herein. A processor, as used herein, may be understood to be a hardware component. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the network node  101 . One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the network node  101 . 
     The network node  101  may further comprise a memory  1203  comprising one or more memory units. The memory  1203  is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the network node  101 . 
     In some embodiments, the network node  101  may receive information from, e.g. the UE  103  and/or another network node, through a receiving port  1204 . In some embodiments, the receiving port  1204  may be, for example, connected to one or more antennas in network node  101 . In other embodiments, the network node  101  may receive information from another structure in the communications system  100  the receiving port  1204 . Since the receiving port  1204  may be in communication with the processor  1201 , the receiving port  1204  may then send the received information to the processor  1201 . The receiving port  1204  may also be configured to receive other information. 
     The processor  1201  in the network node  101  may be further configured to transmit or send information to e.g. the UE  103 , or another structure in the communications system  100 , through a sending port  1205 , which may be in communication with the processor  1201  and the memory  1203 . 
     The network node  101  may comprise a determining unit  1213 , a providing unit  1215 , a receiving unit  1218 , other units  1220  etc. 
     The network node  101  in the communications system  100  is adapted to determine, e.g. by means of the determining unit  1213 , a BWP configuration, wherein the BWP configuration comprises at least one initial BWP and at least one non-initial BWP; provide, e.g. by means of the providing unit  1215 , e.g. by transmitting, information indicating the determined BWP configuration to the UE  103 ; and to receive, e.g. by means of the receiving unit  1218 , a RA preamble message from the UE  103  according to the determined BWP configuration. The information provided, or transmitted, to the UE  103  may be transmitted directly to the UE  103  or via some other node or memory unit. 
     In some embodiments, the BWP configuration may comprise: a primary initial BWP, at least one secondary initial BWPs, and at least one non-initial BWP. In other embodiments, the BWP configuration may comprise a primary initial BWP; a first non-initial BWP; and a second non-initial BWP. In embodiments when the BWP configuration comprises at least one primary and at least one secondary initial BWP, the at least one secondary initial BWPs may be configured via a supplementary carrier; or in a second cell which belongs to a same cell group or a different cell group as the cell where the RA is triggered; or in the same cell as the primary initial BWP. 
     In some embodiments, the initial BWP, e.g. the primary initial BWP, may comprise a LBT sub band. 
     In some embodiments, the initial BWP, e.g. the primary initial BWP, may comprise a plurality of LBT sub bands, e.g. a first LBT sub band and a second LBT sub band. In these embodiments, the network node  101  may be adapted to receive, e.g. b y means of the receiving unit  1218 , the RA preamble on a selected LBT sub band, which has been selected by the UE  103 . For example, the selected sub band, e.g. the first LBT sub band or the second LBT sub band, may be the LBT sub band that wins the LBT. 
     In some embodiments, the non-initial BWP, e.g. the first non-initial BWP and/or the second non-initial BWP, may comprise at least one LBT sub bands. In embodiments when the non-initial BWP comprises a plurality of LBT sub bands, ROs may be configured across multiple LBT sub bands, and the ROs may belong to a same or different PRACH configuration. 
     In some embodiments, at least one of the following parameters may be defined in the PRACH configuration, e.g. according to RRC IE RACH-ConfigGeneric, a first parameter indicating a sub band offset; a second parameter indicating the number of PRACH transmission occasions in one time instance in one LBT sub band; and a reused at least one existing third parameters associated with LBT sub band. The first parameter may be referred to as e.g. msg1-FrequencyStart-sub band. The second parameter may be referred to as e.g. msg1-FDM-sub band. The at least one parameters, e.g. the msg1-FDM-sub band parameter and/or an msg1-FrequencyStart-sub band parameter, may be defined for every sub band or for configured specific sub bands. 
     In some embodiments, a separate PRACH configuration corresponding to e.g., RRC IE RACH-Config Common may be configured in a LBT sub band. The separate PRACH configuration may be associated with a LBT sub band index. 
     The network node  101  may be an NB, eNB, gNB, RNC, access node, RAN node, core network, CN, node, etc., or any other suitable network node. 
     Those skilled in the art will also appreciate that the determining unit  1213 , the providing unit  1215 , the receiving unit  1218 , the other units  3020  etc. described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processor  1201 , perform as described above. One or more of these processors, as well as the other digital hardware, may be comprised in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC). 
     Also, in some embodiments, the different units  1213 - 1220  described above may be implemented as one or more applications running on one or more processors such as the processor  1201 . 
     Thus, the methods according to the embodiments described herein for the network node  101  may be respectively implemented by means of a computer program  1210  product, comprising instructions, i.e., software code portions, which, when executed on at least one processor  1201 , cause the at least one processor  1201  to carry out the actions described herein, as performed by the network node  101 . The computer program  1210  product may be stored on a computer-readable storage medium  1208 . The computer-readable storage medium  1208 , having stored thereon the computer program  1210 , may comprise instructions which, when executed on at least one processor  1201 , cause the at least one processor  1201  to carry out the actions described herein, as performed by the network node  101 . In some embodiments, the computer-readable storage medium  1210  may be a non-transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. In other embodiments, the computer program  1210  product may be stored on a carrier comprising the computer program  1210  just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium  1208 , as described above. 
     The network node  101  may comprise a communication interface configured to facilitate communications between the network node  101  and other nodes or devices, e.g., the UE  103 , or another structure. The interface may, for example, comprise a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard. 
     In other embodiments, the network node  101  may comprise the following arrangement depicted in  FIG. 12   b.  The network node  101  may comprise a processing circuitry  1211 , e.g., one or more processors such as the processor  1201 , in the network node  101  and the memory  1203 . The network node  101  may also comprise a radio circuitry  1214 , which may comprise e.g., the receiving port  1204  and the second sending port  1205 . The processing circuitry  1211  may be configured to, or operable to, perform the method actions according to  FIGS. 5 and 7  in a similar manner as that described in relation to  FIG. 12   a.  The radio circuitry  1214  may be configured to set up and maintain at least a wireless connection with the network node  101 . Circuitry may be understood herein as a hardware component. 
     Hence, embodiments herein also relate to the network node  101  to operate in the communications system. The network node  101  may comprise the processing circuitry  1211  and the memory  1203 . The memory  1203  comprises instructions executable by said processing circuitry  1211 , whereby the network node  101  is further operative to perform the actions described herein in relation to the network node  101 , e.g.  FIGS. 5 and 7 . 
     Further Extensions and Variations 
     Telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments. 
     With reference to  FIG. 13 , in accordance with an embodiment, a communication system  100  comprises a telecommunication network  1310  such as the communications system  100 , for example, a 3GPP-type cellular network, which comprises access network  1311 , such as a radio access network, and core network  1314 . Access network  1311  comprises a plurality of network nodes  101 . For example, base stations  1312   a,    1312   b,    1312   c,  such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area  1313   a,    1313   b,    1313   c.  Each base station  1312   a,    1312   b,    1312   c  is connectable to core network  1314  over a wired or wireless connection  1315 . A plurality of UEs, such as the UE  103  may be comprised in the communications system  100 . In  FIG. 13 , a first UE  1391  located in coverage area  1313   c  is configured to wirelessly connect to, or be paged by, the corresponding base station  1312   c.  A second UE  1392  in coverage area  1313   a  is wirelessly connectable to the corresponding base station  1312   a.  While a plurality of UEs  1391 ,  1392  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 base station  1312 . Any of the UEs  1391 ,  1392  may be considered examples of the UE  103 . 
     Telecommunication network  1310  is itself connected to host computer  1330 , which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer  1330  may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections  1321  and  1322  between telecommunication network  1310  and host computer  1330  may extend directly from core network  1314  to host computer  1330  or may go via an optional intermediate network  1320 . Intermediate network  1320  may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network  1320 , if any, may be a backbone network or the Internet; in particular, intermediate network  1320  may comprise two or more sub-networks (not shown). 
     The communication system of  FIG. 13  as a whole enables connectivity between the connected UEs  1391 ,  1392  and host computer  1330 . The connectivity may be described as an Over-The-Top (OTT) connection  1350 . Host computer  1330  and the connected UEs  1391 ,  1392  are configured to communicate data and/or signaling via OTT connection  1350 , using access network  1311 , core network  1314 , any intermediate network  1320  and possible further infrastructure (not shown) as intermediaries. OTT connection  1350  may be transparent in the sense that the participating communication devices through which OTT connection  1350  passes are unaware of routing of uplink and downlink communications. For example, base station  1312  may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer  1330  to be forwarded (e.g., handed over) to a connected UE  1391 . Similarly, base station  1312  need not be aware of the future routing of an outgoing uplink communication originating from the UE  1391  towards the host computer  1330 . 
     In relation to  FIGS. 14-18  which are described next, it may be understood that the base station may be considered an example of the network node  101 . 
       FIG. 14  illustrates an example of host computer communicating via a base station  101  with a UE  103  over a partially wireless connection in accordance with some embodiments 
     The UE  103  and the network node  101 , e.g., a base station and host computer discussed in the preceding paragraphs will now be described with reference to  FIG. 14 . In communication system  1430 , such as the communications system  100 , host computer  1410  comprises hardware  1415  comprising communication interface  1416  configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system  1400 . Host computer  1410  further comprises processing circuitry  1418 , which may have storage and/or processing capabilities. In particular, processing circuitry  1418  may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer  1410  further comprises software  1411 , which is stored in or accessible by host computer  1410  and executable by processing circuitry  1418 . Software  1411  comprises a host application  1412 . Host application  1412  may be operable to provide a service to a remote user, such as UE  1430  connecting via OTT connection  1450  terminating at UE  1430  and host computer  1410 . In providing the service to the remote user, host application  1412  may provide user data which is transmitted using OTT connection  1450 . 
     Communication system  1400  further comprises the network node  101  exemplified in  FIG. 1414  as a base station  1420  provided in a telecommunication system and comprising hardware  1425  enabling it to communicate with host computer  1410  and with UE  1430 . Hardware  1425  may comprise a communication interface  1426  for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system  1400 , as well as radio interface  1427  for setting up and maintaining at least wireless connection  1470  with the UE  103 , exemplified in  FIG. 14  as a UE  3330  located in a coverage area (not shown in  FIG. 14 ) served by base station  1420 . Communication interface  1426  may be configured to facilitate connection  1460  to host computer  1410 . Connection  1460  may be direct or it may pass through a core network (not shown in  FIG. 14 ) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware  1425  of base station  1420  further comprises a processing circuitry  1428 , which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station  1420  further has software  1421  stored internally or accessible via an external connection. 
     Communication system  1400  further comprises a UE  1430  already referred to. It&#39;s hardware  1435  may comprise a radio interface  1437  configured to set up and maintain wireless connection  1470  with a base station serving a coverage area in which UE  1430  is currently located. Hardware  1435  of UE  1430  further comprises a processing circuitry  1438 , which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE  1430  further comprises software  1431 , which is stored in or accessible by UE  1430  and executable by processing circuitry  1438 . Software  1431  comprises a client application  1432 . Client application  1432  may be operable to provide a service to a human or non-human user via UE  1430 , with the support of host computer  1410 . In host computer  1410 , an executing host application  1412  may communicate with the executing client application  1432  via OTT connection  1450  terminating at UE  1430  and host computer  1410 . In providing the service to the user, client application  1432  may receive request data from host application  1412  and provide user data in response to the request data. OTT connection  1450  may transfer both the request data and the user data. Client application  1432  may interact with the user to generate the user data that it provides. 
     It is noted that host computer  1410 , base station  1420  and UE  1430  illustrated in  FIG. 14  may be similar or identical to host computer  1330 , one of base stations  1312   a,    1312   b,    1312   c  and one of UEs  1391 ,  1392  of  FIG. 13 , respectively. This is to say, the inner workings of these entities may be as shown in  FIG. 14  and independently, the surrounding network topology may be that of  FIG. 13 . 
     In  FIG. 14 , OTT connection  1450  has been drawn abstractly to illustrate the communication between host computer  1410  and UE  1430  via base station  1420 , without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE  1430  or from the service provider operating host computer  1410 , or both. While OTT connection  1450  is active, the network infrastructure may further take decisions by which it dynamically changes the routing, e.g., on the basis of load balancing consideration or reconfiguration of the network. 
     Wireless connection  1470  between UE  1430  and base station  1420  is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE  1430  using OTT connection  1450 , in which wireless connection  1470  forms the last segment. More precisely, the teachings of these embodiments may improve the spectrum efficiency, and latency, and thereby provide benefits such as reduced user waiting time, better responsiveness and extended battery lifetime. 
     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. There may further be an optional network functionality for reconfiguring OTT connection  1450  between host computer  1410  and UE  1430 , in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection  1450  may be implemented in software  1411  and hardware  1415  of host computer  1410  or in software  1431  and hardware  1435  of UE  1430 , or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection  1450  passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software  1411 ,  1431  may compute or estimate the monitored quantities. The reconfiguring of OTT connection  1450  may comprise information indicating message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station  1420 , and it may be unknown or imperceptible to base station  1420 . Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer  1410 &#39;s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software  1411  and  1431  causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection  1450  while it monitors propagation times, errors etc. 
       FIG. 15  illustrates an example of methods implemented in a communication system comprising a host computer, a base station and a user equipment.  FIG. 15  is a flowchart illustrating a method implemented in a communication system. The communication system  100  comprises a host computer, a base station and a UE which may be those described with reference to  FIG. 13  and  FIG. 14 . For simplicity of the present disclosure, only drawing references to  FIG. 15  will be included in this section. In step  1510 , the host computer provides user data. In substep  1511  (which may be optional) of step  1510 , the host computer provides the user data by executing a host application. In step  1520 , the host computer initiates a transmission carrying the user data to the UE. In step  1530  (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step  1540  (which may also be optional), the UE executes a client application associated with the host application executed by the host computer. 
       FIG. 16  illustrates methods implemented in a communication system  100  comprising a host computer, a base station and a user equipment in accordance with some embodiments.  FIG. 16  is a flowchart illustrating a method implemented in a communication system. The communication system  100  comprises a host computer, a base station and a UE which may be those described with reference to  FIG. 13  and  FIG. 14 . In step  1610  of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step  1620 , the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step  1630  (which may be optional), the UE receives the user data carried in the transmission. 
       FIG. 17  illustrates methods implemented in a communication system  100  comprising a host computer, a base station and a user equipment.  FIG. 17  is a flowchart illustrating a method implemented in a communication system  100 . The communication system  100  comprises a host computer, a base station  101  and a UE  103  which may be those described with reference to  FIG. 13  and  FIG. 14 . For simplicity of the present disclosure, only drawing references to  FIG. 17  will be included in this section. In step  1710  (which may be optional), the UE  103  receives input data provided by the host computer. Additionally or alternatively, in step  1720 , the UE  103  provides user data. In substep  1721  (which may be optional) of step  1720 , the UE provides the user data by executing a client application. In substep  1711  (which may be optional) of step  1710 , the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep  1730  (which may be optional), transmission of the user data to the host computer. In step  1740  of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure. 
       FIG. 18  illustrates methods implemented in a communication system  100  comprising a host computer, a base station and a user equipment.  FIG. 18  is a flowchart illustrating a method implemented in a communication system  100 . The communication system  100  comprises a host computer, a base station and a UE which may be those described with reference to  FIG. 13  and  FIG. 14 . In step  1810  (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step  1820  (which may be optional), the base station initiates transmission of the received user data to the host computer. In step  1830  (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station. 
     Some embodiments may be summarized as follows: 
     A base station configured to communicate with a UE  103 , the base station comprising a radio interface and processing circuitry configured to perform one or more of the actions described herein as performed by the network node  101 . 
     A communication system  100  comprising a host computer comprising:
         processing circuitry configured to provide user data; and   a communication interface configured to forward the user data to a cellular network for transmission to a UE  103 ,   wherein the cellular network comprises a base station  101  having a radio interface and processing circuitry, the base station&#39;s processing circuitry configured to perform one or more of the actions described herein as performed by the network node  101 .       

     The communication system  100  may further comprise the base station  101 . 
     The communication system  100  may further comprise the UE  103 , wherein the UE  103  is configured to communicate with the base station  101 . 
     The communication system  100 , wherein:
         the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and   the UE  103  comprises processing circuitry configured to execute a client application associated with the host application.       

     A method implemented in a base station  101 , comprising one or more of the actions described herein as performed by the network node  101 . 
     A method implemented in a communication system  100  comprising a host computer, a base station and a UE  103 , the method comprising:
         at the host computer, providing user data; and   at the host computer, initiating a transmission carrying the user data to the UE  103  via a cellular network comprising the base station  101 . The base station  101  performs one or more of the actions described herein as performed by the network node  101 .       

     The method may further comprise:
         at the base station  101 , transmitting the user data.       

     The user data may be provided at the host computer by executing a host application, and the method may further comprise:
         at the UE  103 , executing a client application associated with the host application.       

     A UE  103  configured to communicate with a base station  101 , the UE  103  comprising a radio interface and processing circuitry configured to perform one or more of the actions described herein as performed by the UE  103 . 
     A communication system  100  comprising a host computer comprising:
         processing circuitry configured to provide user data; and   a communication interface configured to forward user data to a cellular network for transmission to a UE  103 ,   wherein the UE comprises a radio interface and processing circuitry, the UE&#39;s processing circuitry configured to perform one or more of the actions described herein as performed by the UE  103 .       

     The communication system  100  may further comprise the UE  103 . 
     The communication system  100  further comprising a base station  101  configured to communicate with the UE  103 . 
     The communication system  100 , wherein:
         the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and   the UE&#39;s processing circuitry is configured to execute a client application associated with the host application.       

     A method implemented in a UE  103 , comprising one or more of the actions described herein as performed by the UE  103 . 
     A method implemented in a communication system  100  comprising a host computer, a base station  101  and a UE  103 , the method comprising:
         at the host computer, providing user data; and   at the host computer, initiating a transmission carrying the user data to the UE  103  via a cellular network comprising the base station, wherein the UE  103  performs one or more of the actions described herein as performed by the UE  103 .       

     The method may further comprise:
         at the UE  103 , receiving the user data from the base station  101 .       

     A UE  103  configured to communicate with a base station  101 , the UE  103  comprising a radio interface and processing circuitry configured to perform one or more of the actions described herein as performed by the UE  103 . 
     A communication system  100  comprising a host computer comprising:
         a communication interface configured to receive user data originating from a transmission from a UE  103  to a base station  101 ,   wherein the UE  103  comprises a radio interface and processing circuitry, the UE&#39;s processing circuitry configured to perform one or more of the actions described herein as performed by the UE  103 .       

     The communication system  100  may further comprise the UE  103 . 
     The communication system  100  may further comprise the base station  101 , wherein the base station  101  comprises a radio interface configured to communicate with the UE  103  and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE  103  to the base station. 
     The communication system  100 , wherein:
         the processing circuitry of the host computer is configured to execute a host application; and   the UE&#39;s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.       

     The communication system  100 , wherein:
         the processing circuitry of the host computer is configured to execute a host application, thereby providing request data; and   the UE&#39;s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.       

     A method implemented in a UE  103 , comprising one or more of the actions described herein as performed by the UE  103 . 
     The method may further comprise:
         providing user data; and   forwarding the user data to a host computer via the transmission to the base station  101 .       

     A method implemented in a communication system  100  comprising a host computer, a base station  101  and a UE  103 , the method comprising:
         at the host computer, receiving user data transmitted to the base station  101  from the UE  103 , wherein the UE  103  performs one or more of the actions described herein as performed by the UE  103 .       

     The method may further comprise:
         at the UE  103 , providing the user data to the base station  101 .       

     The method may further comprise:
         at the UE  103 , executing a client application, thereby providing the user data to be transmitted; and   at the host computer, executing a host application associated with the client application.       

     The method may further comprise:
         at the UE  103 , executing a client application; and   at the UE  103 , receiving input data to the client application, the input data being provided at the host computer by executing a host application associated with the client application,   the user data to be transmitted is provided by the client application in response to the input data.       

     A base station  101  configured to communicate with a UE  103 , the base station  101  comprising a radio interface and processing circuitry configured to perform one or more of the actions described herein as performed by the network node  101 . 
     A communication system  100  comprising a host computer comprising a communication interface configured to receive user data originating from a transmission from a UE  103  to a base station, wherein the base station  101  comprises a radio interface and processing circuitry, the base station&#39;s processing circuitry configured to perform one or more of the actions described herein as performed by the network node  101 . 
     The communication system  100  may further comprise the base station  101 . 
     The communication system  100  may further comprise the UE  103 . The UE  103  is configured to communicate with the base station  101 . 
     The communication system  100  wherein:
         the processing circuitry of the host computer is configured to execute a host application;   the UE  103  is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.       

     A method implemented in a base station  101 , comprising one or more of the actions described herein as performed by any of the network node  101 . 
     A method implemented in a communication system  100  comprising a host computer, a base station  101  and a UE  103 , the method comprising:
         at the host computer, receiving, from the base station  101 , user data originating from a transmission which the base station has received from the UE  103 , wherein the UE  103  performs one or more of the actions described herein as performed by the UE  103 .       

     The method may further comprise:
         at the base station  101 , receiving the user data from the UE  103 .       

     The method may further comprise:
         at the base station  101 , initiating a transmission of the received user data to the host computer.       

     The embodiments herein relate to methods to configure PRACH across different LBT sub-bands. They relate to channel occupancy time (COT) and random access (RA). The method described as being performed by the UE  103  may also be described as being performed by the Layer 2 module comprised in the UE  103 . 
     Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. 
     Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description. In general, the usage of “first”, “second”, “third”, “fourth”, and/or “fifth” herein may be understood to be an arbitrary way to denote different elements or entities, and may be understood to not confer a cumulative or chronological character to the nouns they modify, unless otherwise noted, based on context. 
     Several embodiments are comprised herein. It should be noted that the examples herein are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments 
     The embodiments herein are not limited to the above described embodiments. Various alternatives, modifications and equivalents may be used. Therefore, the above embodiments should not be taken as limiting the scope of the embodiments. A feature from one embodiment may be combined with one or more features of any other embodiment. 
     The term “at least one of A and B” should be understood to mean “only A, only B, or both A and B.”, where A and B are any parameter, number, indication used herein etc. 
     It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components, but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. It should also be noted that the words “a” or “an” preceding an element do not exclude the presence of a plurality of such elements. 
     The term “configured to” used herein may also be referred to as “arranged to”, “adapted to”, “capable of” or “operative to”. 
     It should also be emphasised that the steps of the methods may, without departing from the embodiments herein, be performed in another order than the order in which they appear herein. 
     Some example embodiments according to the present disclosure is presented herein below. 
     1. A method performed by a User Equipment, UE, ( 103 ) in a communications system ( 100 ), the method comprises:
         obtaining ( 502 ), e.g. by receiving directly or via some other node or memory unit, information indicating a Bandwidth Part, BWP, configuration from the network node ( 101 ), wherein the BWP configuration comprises one or multiple initial BWPs and one or multiple non-initial BWPs; and   initiating ( 504 ) a Random Access, RA, procedure according to the obtained BWP configuration, e.g. by transmitting a RA preamble message to the network node ( 101 ).       

     2. The method according to any of the preceding embodiments, wherein the configuration for BWP comprises a primary initial BWP, one or multiple secondary initial BWPs, and a first non-initial BWP. 
     3. The method according to any of the preceding embodiments, wherein the configuration for BWP comprises a primary initial BWP; a first non-initial BWP; and a second non-initial BWP. 
     4. The method according to any of the preceding embodiments, wherein the one or multiple secondary initial BWPs is configured via a supplementary carrier, in a second cell which belongs to a same cell group or a different cell group as the cell where the RA is triggered; or in the same cell as the primary initial BWP. 
     5. The method according to any of the preceding embodiments, wherein the initial BWP, e.g. the primary initial BWP, comprises a LBT sub band. 
     6. The method according to any of the preceding embodiments, wherein the initial BWP, e.g. the primary initial BWP, comprises a first LBT sub band and a second LBT sub band. 
     7. The method according to any of the preceding embodiments, when the initial BWP, e.g. the primary initial BWP, comprises a first LBT sub band and a second LBT sub band, then the method comprises:
         selecting ( 503 ) the first LBT sub band or the second LBT sub band; and   transmitting ( 504 ) the RA preamble to the network node ( 101 ) on the selected first LBT sub band or second LBT sub band.       

     8. The method according to any of the preceding embodiments, wherein the selected first LBT sub band or second LBT sub band is the LBT sub band that wins the LBT. 
     9. The method according to any of the preceding embodiments, wherein the non-initial BWP, e.g. the first non-initial BWP and/or the second non-initial BWP, comprises one or multiple LBT sub bands. 
     10. The method according to any of the preceding embodiments, when the non-initial BWP comprises multiple LBT sub bands, then RACH occasions, ROs, are configured across multiple LBT sub bands, and the ROs belong to a same or different PRACH configuration. 
     11. The method according to any of the preceding embodiments, wherein at least one of the following parameters is defined in the PRACH configuration, e.g. according to RRC IE RACH-ConfigGeneric:
         a parameter indicating a sub band offset, wherein the parameter may be referred to as e.g. msg1-FrequencyStart-sub band; and/or   a parameter indicating the number of PRACH transmission occasions in one time instance in one LBT sub band, wherein the parameter may be referred to as e.g. msg1-FDM-sub band; and/or   a reused one or multiple existing parameters associated with LBT sub band.       

     12. The method according to any of the preceding embodiments, wherein the one or multiple other parameters, e.g. the msg1-FDM-sub band parameter and/or an msg1-FrequencyStart-sub band parameter, are defined for every sub band or for configured specific sub bands. 
     13. The method according to any of the preceding embodiments, wherein a separate PRACH configuration corresponding to e.g., RRC IE RACH-Config Common is configured in a LBT sub band, wherein the separate PRACH configuration is associated with a LBT sub band index. 
     14. The method according to any of the preceding embodiments, wherein the communications system ( 100 ) is a 2G network, a 3G network, a 4G network, a 5G network, a 6G network or any other legacy, current of future network. 
     15. A method performed by a network node ( 101 ) in a communications system ( 100 ), the method comprising:
         determining ( 501 ) a Bandwidth Part, BWP, configuration, wherein the BWP configuration comprises one or multiple initial BWPs and one or multiple non-initial BWPs;   providing ( 502 ), e.g. by transmitting directly or via some other node or memory unit, information indicating the determined BWP configuration to the UE ( 103 ), wherein the BWP configuration comprises one or multiple initial BWPs and one or multiple non-initial BWPs; and   receiving ( 504 ) a RA preamble message from the UE ( 103 ) according to the provided BWP configuration.       

     16. The method according to any of the preceding embodiments, wherein the configuration for BWP comprises a primary initial BWP, one or multiple secondary initial BWPs, and a first non-initial BWP. 
     17. The method according to any of the preceding embodiments, wherein the configuration for BWP comprises a primary initial BWP; a first non-initial BWP; and a second non-initial BWP. 
     18. The method according to any of the preceding embodiments, wherein the one or multiple secondary initial BWPs is configured via a supplementary carrier, in a second cell which belongs to a same cell group or a different cell group as the cell where the RA is triggered; or in the same cell as the primary initial BWP. 
     19. The method according to any of the preceding embodiments, wherein the initial BWP, e.g. the primary initial BWP, comprises a LBT sub band. 
     20. The method according to any of the preceding embodiments, wherein the initial BWP, e.g. the primary initial BWP, comprises a first LBT sub band and a second LBT sub band, 
     21. The method according to any of the preceding embodiments, when the initial BWP, e.g. the primary initial BWP, comprises a first LBT sub band and a second LBT sub band, then the method comprises:
         receiving ( 504 ) the RA preamble to the network node ( 101 ) on a selected first LBT sub band or second LBT sub band which has been selected by the UE ( 103 ).       

     22. The method according to any of the preceding embodiments, wherein the selected first LBT sub band or second LBT sub band is the LBT sub band that wins the LBT. 
     23. The method according to any of the preceding embodiments, wherein the non-initial BWP, e.g. the first non-initial BWP and/or the second non-initial BWP, comprises one or multiple LBT sub bands. 
     24. The method according to any of the preceding embodiments, when the non-initial BWP comprises multiple LBT sub bands, then RACH occasions, ROs, are configured across multiple LBT sub bands, and the ROs belong to a same or different PRACH configuration. 
     25. The method according to any of the preceding embodiments, wherein at least one of the following parameters is defined in the PRACH configuration, e.g. according to RRC IE RACH-ConfigGeneric:
         a parameter indicating a sub band offset, wherein the parameter may be referred to as e.g. msg1-FrequencyStart-sub band; and/or   a parameter indicating the number of PRACH transmission occasions in one time instance in one LBT sub band, wherein the parameter may be referred to as e.g. msg1-FDM-sub band; and/or   a reused one or multiple existing parameters associated with LBT sub band.       

     26. The method according to any of the preceding embodiments, wherein the one or multiple other parameters, e.g. the msg1-FDM-sub band parameter and/or an msg1-FrequencyStart-sub band parameter, are defined for every sub band or for configured specific sub bands. 
     27. The method according to any of the preceding embodiments, wherein a separate PRACH configuration corresponding to e.g., RRC IE RACH-Config Common is configured in a LBT sub band, wherein the separate PRACH configuration is associated with a LBT sub band index. 
     28. The method according to any of the preceding embodiments, wherein the communications system ( 100 ) is a 2G network, a 3G network, a 4G network, a 5G network, a 6G network or any other legacy, current of future network. 
     29. The method according to any of the preceding embodiments, wherein the network node ( 101 ) is an NB, eNB, gNB, RNC, access node, RAN node, core network, CN, node, etc., or any other suitable network node. 
     30. A User Equipment, UE, ( 103 ) in a communications system ( 100 ), wherein the UE ( 103 ) is adapted to:
         obtain, e.g. by receiving directly or via some other node or memory unit, information indicating a Bandwidth Part, BWP, configuration from the network node ( 101 ), wherein the BWP configuration comprises one or multiple initial BWPs and one or multiple non-initial BWPs; and to   initiate a Random Access, RA, procedure according to the obtained BWP configuration, e.g. by transmitting a RA preamble message to the network node ( 101 ).       

     31. The UE ( 103 ) according to any of the preceding embodiments, wherein the configuration for BWP comprises a primary initial BWP, one or multiple secondary initial BWPs, and a first non-initial BWP. 
     32. The UE ( 103 ) according to any of the preceding embodiments, wherein the configuration for BWP comprises a primary initial BWP; a first non-initial BWP; and a second non-initial BWP. 
     33. The UE ( 103 ) according to any of the preceding embodiments, wherein the one or multiple secondary initial BWPs is configured via a supplementary carrier, in a second cell which belongs to a same cell group or a different cell group as the cell where the RA is triggered; or in the same cell as the primary initial BWP. 
     34. The UE ( 103 ) according to any of the preceding embodiments, wherein the initial BWP, e.g. the primary initial BWP, comprises a LBT sub band. 
     35. The UE ( 103 ) according to any of the preceding embodiments, wherein the initial BWP, e.g. the primary initial BWP, comprises a first LBT sub band and a second LBT sub band, 
     36. The UE ( 103 ) according to any of the preceding embodiments, when the initial BWP, e.g. the primary initial BWP, comprises a first LBT sub band and a second LBT sub band, then the UE ( 103 ) is adapted to:
         selecting ( 503 ) the first LBT sub band or the second LBT sub band; and   transmitting ( 504 ) the RA preamble to the network node ( 101 ) on the selected first LBT sub band or second LBT sub band.       

     37. The UE ( 103 ) according to any of the preceding embodiments, wherein the selected first LBT sub band or second LBT sub band is the LBT sub band that wins the LBT. 
     38. The UE ( 103 ) according to any of the preceding embodiments, wherein the non-initial BWP, e.g. the first non-initial BWP and/or the second non-initial BWP, comprises one or multiple LBT sub bands. 
     39. The UE ( 103 ) according to any of the preceding embodiments, when the non-initial BWP comprises multiple LBT sub bands, then RACH occasions, ROs, are configured across multiple LBT sub bands, and the ROs belong to a same or different PRACH configuration. 
     40. The UE ( 103 ) according to any of the preceding embodiments, wherein at least one of the following parameters is defined in the PRACH configuration, e.g. according to RRC IE RACH-ConfigGeneric:
         a parameter indicating a sub band offset, wherein the parameter may be referred to as e.g. msg1-FrequencyStart-sub band; and/or   a parameter indicating the number of PRACH transmission occasions in one time instance in one LBT sub band, wherein the parameter may be referred to as e.g. msg1-FDM-sub band; and/or   a reused one or multiple existing parameters associated with LBT sub band.       

     41. The UE ( 103 ) according to any of the preceding embodiments, wherein the one or multiple other parameters, e.g. the msg1-FDM-sub band parameter and/or an msg1-FrequencyStart-sub band parameter, are defined for every sub band or for configured specific sub bands. 
     42. The UE ( 103 ) according to any of the preceding embodiments, wherein a separate PRACH configuration corresponding to e.g., RRC IE RACH-Config Common is configured in a LBT sub band, wherein the separate PRACH configuration is associated with a LBT sub band index. 
     43. The UE ( 103 ) according to any of the preceding embodiments, wherein the communications system ( 100 ) is a 2G network, a 3G network, a 4G network, a 5G network, a 6G network or any other legacy, current of future network. 
     44. A network node ( 101 ) in a communications system ( 100 ), the network node ( 101 ) adapted to:
         determine a Bandwidth Part, BWP, configuration, wherein the BWP configuration comprises one or multiple initial BWPs and one or multiple non-initial BWPs;   provide, e.g. by transmitting directly or via some other node or memory unit, information indicating the determined BWP configuration to the UE ( 103 ), wherein the BWP configuration comprises one or multiple initial BWPs and one or multiple non-initial BWPs; and to   receive a RA preamble message from the UE ( 103 ) according to the provided BWP configuration.       

     45. The network node ( 101 ) according to any of the preceding embodiments, wherein the configuration for BWP comprises a primary initial BWP, one or multiple secondary initial BWPs, and a first non-initial BWP. 
     46. The network node ( 101 ) according to any of the preceding embodiments, wherein the configuration for BWP comprises a primary initial BWP; a first non-initial BWP; and a second non-initial BWP. 
     47. The network node ( 101 ) according to any of the preceding embodiments, wherein the one or multiple secondary initial BWPs is configured via a supplementary carrier, in a second cell which belongs to a same cell group or a different cell group as the cell where the RA is triggered; or in the same cell as the primary initial BWP. 
     48. The network node ( 101 ) according to any of the preceding embodiments, wherein the initial BWP, e.g. the primary initial BWP, comprises a LBT sub band. 
     49. The network node ( 101 ) according to any of the preceding embodiments, wherein the initial BWP, e.g. the primary initial BWP, comprises a first LBT sub band and a second LBT sub band, 
     50. The network node ( 101 ) according to any of the preceding embodiments, when the initial BWP, e.g. the primary initial BWP, comprises a first LBT sub band and a second LBT sub band, then the network node ( 101 ) is adapted to:
         receive the RA preamble to the network node ( 101 ) on a selected first LBT sub band or second LBT sub band which has been selected by the UE ( 103 ).       

     51. The network node ( 101 ) according to any of the preceding embodiments, wherein the selected first LBT sub band or second LBT sub band is the LBT sub band that wins the LBT. 
     52. The network node ( 101 ) according to any of the preceding embodiments, wherein the non-initial BWP, e.g. the first non-initial BWP and/or the second non-initial BWP, comprises one or multiple LBT sub bands. 
     53. The network node ( 101 ) according to any of the preceding embodiments, when the non-initial BWP comprises multiple LBT sub bands, then RACH occasions, ROs, are configured across multiple LBT sub bands, and the ROs belong to a same or different PRACH configuration. 
     54. The network node ( 101 ) according to any of the preceding embodiments, wherein at least one of the following parameters is defined in the PRACH configuration, e.g. according to RRC IE RACH-ConfigGeneric:
         a parameter indicating a sub band offset, wherein the parameter may be referred to as e.g. msg1-FrequencyStart-sub band; and/or   a parameter indicating the number of PRACH transmission occasions in one time instance in one LBT sub band, wherein the parameter may be referred to as e.g. msg1-FDM-sub band; and/or   a reused one or multiple existing parameters associated with LBT sub band.       

     55. The network node ( 101 ) according to any of the preceding embodiments, wherein the one or multiple other parameters, e.g. the msg1-FDM-sub band parameter and/or an msg1-FrequencyStart-sub band parameter, are defined for every sub band or for configured specific sub bands. 
     56. The network node ( 101 ) according to any of the preceding embodiments, wherein a separate PRACH configuration corresponding to e.g., RRC IE RACH-Config Common is configured in a LBT sub band, wherein the separate PRACH configuration is associated with a LBT sub band index. 
     57. The network node ( 101 ) according to any of the preceding embodiments, wherein the communications system ( 100 ) is a 2G network, a 3G network, a 4G network, a 5G network, a 6G network or any other legacy, current of future network. 
     58. The network node ( 101 ) according to any of the preceding embodiments, wherein the network node ( 101 ) is an NB, eNB, gNB, RNC, access node, RAN node, core network, CN, node, etc., or any other suitable network node. 
     59. A first computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of embodiments 1-14. 
     60. A first carrier comprising the first computer program of embodiment 59, wherein the first carrier is one of an electronic signal, optical signal, radio signal or computer readable storage medium. 
     61. A second computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of embodiments 15-29. 
     62. A second carrier comprising the second computer program of embodiment 61, wherein the second carrier is one of an electronic signal, optical signal, radio signal or computer readable storage medium.