Channel access in unlicensed spectrum for mmW operation

Abstract

The present application describes at least one method for obtaining channel access in a network. The method includes the step of selecting a spatial filter from a first set of spatial filters via a gNodeB to perform listen before talk (LBT). The method includes the step of detecting a channel in an idle state via the gNodeB. The method also includes the step of obtaining a directional channel occupancy time (COT) in the channel in the direction of the selected spatial filter. The method also includes the step of sending a channel access indicator transmission (CAI-T) to a node on a beam within the COT via a spatial filter in a second set of spatial filters. The method also includes the step of receiving a channel access indicator response (CAI-R) from a node. The method also includes the step of sensing via a short channel and sensing that a channel is idle via the spatial filter or another spatial filter in the second set of spatial filters. The method also includes the step of sending information to a node via the channel using one or more spatial filters in the second set of spatial filters. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 62 / 888,044, filed on August 16, 2019, “Channel Access for Unlicensed Spectrum in mmW Operation,” the contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to methods, devices and systems for channel access of unlicensed spectrum in mmW operations. Background Art

[0004] The use of directional sensing in mmW spectrum is a logical basis for achieving better spatial reuse. However, directional sensing poses challenges in designing the network. These challenges include: (i) efficient determination of spatial filters for directional sensing; (ii) acquisition of channel occupancy time (COT) in multiple spatial directions and in multiple subbands; and (iii) efficient management of hidden nodes. Thus, it is desirable to have an architecture and signaling approach that enables directional reuse and ensures fair coexistence with other similar or different technologies.

[0005] Large antenna arrays in the mmW spectrum produce highly directional beams with high power bandwidth (HPBW) ranging from 5-30 degrees and 10-20dBi gain. With highly narrow beams, the receiver can effectively tune its spatial filters to eliminate interference from other directions. While hidden nodes are less controversial in centralized networks when compared to WiGiG networks, problems arise when multiple networks share spectrum in an uncoordinated manner and the node density is high. Nodes can belong to other NR-U networks or WiGiG networks. Nodes can also belong to the same network. For example, in a non-ideal backhaul deployment, the second transmit receive point (TRP2) can be a hidden node for UE1 communicating with TRP1.

[0006] Additionally, autonomous UL transmissions with configured grants from multiple UEs may cause interference. Device-to-device (D2D) sidelinks may also be affected by hidden nodes due to less coordination between nodes. A strategy for channel access in mmW spectrum is desired to overcome the issues based on deployment scenarios, traffic, and environment. Summary of the invention

[0007] One aspect of the present application relates to a method for obtaining channel access in a network. The method includes the step of selecting a spatial filter from a first set of spatial filters via a gNodeB to perform listen before talk (LBT). The method includes the step of detecting a channel in an idle state via a gNodeB. The method also includes the step of obtaining a directional channel occupancy time (COT) in the channel in the direction of the selected spatial filter. The method also includes the step of sending a channel access indicator transmission (CAI-T) to a node on a beam within the COT via a spatial filter in a second set of spatial filters. The method also includes the step of receiving a channel access indicator response (CAI-R) from a node. The method also includes the step of sensing via a short channel and sensing that a channel is clear via the spatial filter or another spatial filter in the second set of spatial filters. The method also includes the step of sending information to a node via the channel using one or more spatial filters in the second set of spatial filters. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each of which is configured to perform the actions of the method.

[0008] Another aspect of the present application relates to a device. The device includes a non-temporary memory for obtaining channel access in a network. The device also includes a processor that is operably coupled to the non-temporary memory and is configured to execute instructions. One of the instructions includes receiving CAI-T from a gNodeB on a beam within the COT of a channel. Another instruction in the instructions includes selecting a spatial filter from a set of spatial filters. Another instruction in the instructions includes sensing via a short channel and sensing via a selected spatial filter in the set of spatial filters. Another instruction in the instructions includes sending a channel CAI-R to a gNodeB using the selected spatial filter or another spatial filter in the set of spatial filters. Another instruction in the instructions includes receiving information from a gNodeB. Further instructions include sensing via short channel sensing and a second spatial filter in the set of spatial filters. Still further instructions include determining that a channel is idle. Yet another instruction includes sending one or more of data and control information to a gNodeB via a third filter in the set of spatial filters. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each of which is configured to perform the actions of the method.

[0009] Another aspect of the present application relates to a device including a non-temporary memory for obtaining channel access in a network. The device also includes a processor that is operably coupled to the non-temporary memory and is configured to execute instructions. One of the instructions includes selecting a spatial filter from a first group of spatial filters to perform LBT. Another instruction in the instructions includes obtaining a directional COT in a channel in the direction of the selected spatial filter. Another instruction in the instructions includes sending CAI-T to a node on a beam within the COT via a spatial filter in a second group of spatial filters. Another instruction includes receiving CAI-R via a node. Yet another instruction includes sensing via a short channel and using the spatial filter or another spatial filter in the second group of spatial filters to sense that the channel is idle. Further instructions include using one or more spatial filters in the second group of spatial filters to send information to a node via the channel. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each of which is configured to perform the actions of the method.

[0010] The present invention summary section is provided to introduce a number of concepts further described in the detailed description section below in a simplified form. The present invention summary section is not intended to limit the scope of the claimed subject matter. The present application described herein meets the above needs to a large extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to facilitate a better understanding of the present application, reference is now made to the accompanying drawings, in which the same elements are referenced with the same reference numerals. These drawings should not be construed as limiting the present application, but are merely exemplary.

[0012] Figure 1A An example communication system in accordance with one aspect of the present application is illustrated.

[0013] Figure 1B An example device configured for wireless communication according to one aspect of the present disclosure is illustrated.

[0014] Figure 1C A system diagram illustrating a radio access network and a core network according to one aspect of the present application.

[0015] Figure 1D A system diagram illustrating a radio access network and a core network according to one aspect of the present application.

[0016] Figure 1E A system diagram illustrating a radio access network and a core network according to one aspect of the present application.

[0017] Figure 1F The diagram illustrates an aspect of the present application, which is similar to the above Figure 1A , 1C , 1D, and 1E are block diagrams of example computing systems that communicate with one or more networks.

[0018] Figure 1G An example communication system is illustrated in accordance with an embodiment.

[0019] Figure 2A -B illustrates the LBT mechanism of LTE and NR CAT4 and CAT2 in a shared COT according to one aspect of the present application.

[0020] Figure 3A -B illustrates multi-TRP transmission and multi-panel transmission according to one aspect of the present application respectively.

[0021] Figure 4A -C illustrate exposed nodes and omnidirectional sensing, spatial reuse, and hidden nodes and directional sensing, respectively, according to one aspect of the present application.

[0022] Figure 5 A spatial filter providing a wide beam pattern and a narrow beam pattern with an angular spread Di contained within an angular spread L is illustrated in accordance with one aspect of the present application.

[0023] Fig. 6A -B respectively illustrate the process of LBT and channel access using the spatial filter L according to one aspect of the present application - FBLBT signaling between the gNB and the UE, and the transmission spatial filter containment within the signaling LBT spatial filter containment between the gNB and the UE.

[0024] Figure 7 The diagram illustrates a timeline of the COT acquired by a gNB using directional LBT-FBLBT in accordance with one aspect of the present application.

[0025] Figure 8 The diagram illustrates a configuration for sending CAI-T to multiple UEs in a COT according to one aspect of the present application.

[0026] Fig. 9 The diagram illustrates signaling between a TRP and a UE utilizing a FBLBT scheme in accordance with one aspect of the present application—the gNB does not send data on beams for which it does not receive a CAI-R.

[0027] Fig.10 The diagram illustrates the signaling between the TRP and the UE using the FBLBT scheme in accordance with one aspect of the present application - the gNB only receives the CAI-R from UE1 on D1, and the gNB does not send data to UE2.

[0028] Fig.11 The diagram illustrates the signaling between the TRP and the UE using the FBLBT scheme in accordance with one aspect of the present application - if even one UE does not send CAI-R, the gNB does not send in a certain direction.

[0029] Fig.12 The diagram illustrates that in accordance with one aspect of the present application, when CAI-R indicates a busy channel for the UE, the gNB removes S2 from its COT.

[0030] Fig.13A -B illustrate the process of, according to one aspect of the present application, when CAI-R indicates a busy channel at the UE, when CAT4 LBT is repeated if CAI-R indicates a busy channel, and when CAI-R is retransmitted if CAI-R indicates a busy channel.

[0031] Fig.14A -B illustrate the timeline of the FBLBT process when CAT4 LBT is repeated if CAI-R indicates a busy channel, and when CAI-R is retransmitted if CAI-R indicates a busy channel, respectively, according to one aspect of the present application.

[0032] Fig.15 The diagram illustrates sending CAI-T, CAI-R using CAT2 sensing according to one aspect of the present application.

[0033] Fig.16A -B respectively illustrates the process of LBT and channel access using the spatial filter L according to one aspect of the present application - the transmission spatial filter inclusion within the LBT spatial filter inclusion, and the NFBLBT for signaling between the gNB and the UE.

[0034] Fig.17 The diagram illustrates a timeline of directional CIOT acquired by a gNB using directional LBT-NFBLBT in accordance with one aspect of the present application.

[0035] Fig.18 The diagram illustrates a NFBLBT on a link with TRP1 and a FBLBT on a link with TRP2 according to one aspect of the present application.

[0036] Fig.19 The diagram illustrates spatial filters L1, L2, L3 and L4 for LBT according to one aspect of the present application, where the UE starts with a wide beam and if the channel is busy, the UE tries LBBT with a narrower beam at a different spatial orientation.

[0037] Fig. 20The diagram illustrates a timeline showing adaptation of the LBT spatial filter during an initial CCA period in accordance with one aspect of the present application.

[0038] Fig.21 The diagram illustrates a UE timeline showing adaptation of an LBT spatial filter based on idle or busy channels during an extended CCA period in accordance with one aspect of the present application.

[0039] Fig. 22 The diagram illustrates the UE process of channel access using LBT beam adaptation according to one aspect of the present application.

[0040] Fig.23 The diagram illustrates the process of CWS adjustment based on CAI-R according to one aspect of the present application.

[0041] Fig.24A -C illustrates directional COT acquisition in multiple spatial directions and in sub-bands according to one aspect of the present application.

[0042] Fig.25A -B respectively illustrate multi-directional COT acquisition using CAT2 for additional directional COTs, and CAT4-based LBT for all directions, with the CAT4-based LBT having self-delay to align the directional COTs according to one aspect of the present application.

[0043] Fig.26 The diagram illustrates sub-band aggregation in FBLBT according to one aspect of the present application.

[0044] Fig.27A -B illustrate virtual sensing using network configuration according to one aspect of the present application, and TRP1 sensing the occupancy of TRP2 in S1 and S2 using spatial filter L1.

[0045] Fig.28A -B respectively illustrate a COT separated in a frequency network configuration according to one aspect of the present application, and an example in which TRP1 does not use D1 to transmit in S1 and S2 because TRP1 senses the occupancy of TRP2.

[0046] Fig.29A -B respectively illustrate the spatial reuse through non-interfering directional COT configured for the TRP1 network according to one aspect of the present application, and when TRP1 does not use L1 for transmission because TRP1 senses the occupancy of TRP2.

[0047] Fig.30 The diagram illustrates a process of spatial reuse according to one aspect of the present application, including determining spatial, temporal, and frequency resources for channel access after virtual sensing. DETAILED DESCRIPTION

[0048] Here, detailed description of example embodiments will be discussed with reference to various figures, embodiments and aspects. Although this description provides detailed examples of possible implementations, it should be understood that these details are exemplary and do not limit the scope of the present application.

[0049] References in this specification to "one embodiment," "an embodiment," "one or more embodiments," etc., mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present disclosure. Furthermore, the term "embodiment" in different places in the specification does not necessarily refer to the same embodiment. That is, various features that may be exhibited by some embodiments but not by other embodiments are described. References in this specification to "an aspect," "an aspect," or "one or more aspects," etc. include one or more embodiments listed below.

[0050] Definition / Acronym

[0051] Provided below in Table 1 are definitions of terms and phrases commonly used in this application.

[0052]

[0053]

[0054]

[0055] Table 1

[0056] The various aspects of this application relate to at least the following aspects:

[0057] Feedback-based LBT (FBLBT) for channel access is enabled by sending CAI-T to the receiver and receiving CAI-R from the receiver. CAI-R indicates the subbands in which the channel is idle for the receiver. CAI-R can also indicate the interference level at the receiver.

[0058] Non-feedback based LBT (NFBLBT) that does not require CAI-T and CAI-R communications may also be supported. According to the present application, it is contemplated that a node or network may semi-statically or dynamically switch between using FBLBT and NFBLBT.

[0059] The transmitter sends a channel reservation signal and COT information to confirm that it has acquired the channel. The COT information can carry the duration, subband, and spatial filter information of the channel access. The spatial filter information can be indicated in association with a quasi-co-site (QCL) reference signal (RS) such as SSB, CS-RS, DMRS.

[0060] The spatial domain filter for LBT determines the spatial directionality of the acquired COT. The spatial filter can be adapted to increase or decrease the beam width or angular spread and can be used to steer the beam in space. The contention window size can be adapted based on feedback from CAI-R. Nodes can access the channel simultaneously in multiple directions.

[0061] A node can perform random backoff based (CAT4) access in one spatial direction to access the channel. A node can perform CAT2 based sensing to simultaneously acquire the channel in another spatial direction.

[0062] The COT information can be provided as a part of a reserved signal or a control signal. It can be broadcast or multicast or UE-specific control information.

[0063] The node maintains a table of valid COT indications from other nodes and the corresponding spatial filters used to receive them. Before their COT expires, the nodes will not access channels corresponding to those spatial filters, COT durations and subbands in the table.

[0064] General architecture

[0065] The Third Generation Partnership Project (3GPP) develops technical standards for cellular telecommunication network technologies, including radio access, core transport networks, and service capabilities - including work on codecs, security, and quality of service. Recent radio access technology (RAT) standards include WCDMA (commonly referred to as 3G), LTE (commonly referred to as 4G), LTE-Advanced standards, and New Radio (NR), also referred to as "5G". The development of the 3GPP NR standards is expected to continue and include the definition of next generation radio access technologies (new RATs), which are expected to include the provision of new flexible radio access below 7 GHz, and the provision of new ultra-mobile broadband radio access above 7 GHz. Flexible radio access is expected to consist of new non-backward compatible radio access in new spectrum below 7 GHz, and is expected to include different operating modes that can be multiplexed together in the same spectrum to address a wide set of 3GPP NR use cases with different requirements. Ultra-mobile broadband is expected to include cmWave and mmWave spectrum, which will provide opportunities for ultra-mobile broadband access for, for example, indoor applications and hotspots. In particular, ultra-mobile broadband is expected to share a common design framework with sub-7 GHz flexible radio access, with cmWave- and mmWave-specific design optimizations.

[0066] 3GPP has identified a variety of use cases that NR is expected to support, resulting in a wide variety of user experience requirements for data rates, latency, and mobility. Use cases include the following general categories: enhanced mobile broadband (eMBB) ultra-reliable low latency communications (URLLC), massive machine type communications (mMTC), network operations (e.g., network slicing, routing, migration and interworking, energy saving), and enhanced vehicle-to-everything (eV2X) communications, which can include any of vehicle-to-vehicle communications (V2V), vehicle-to-infrastructure communications (V2I), vehicle-to-network communications (V2N), vehicle-to-pedestrian communications (V2P), and communications between vehicles and other entities. Specific services and applications in these categories include, for example, surveillance and sensor networks, device remote control, two-way remote control, personal cloud computing, video streaming, wireless cloud office, first responder connectivity, car emergency calls, disaster alerts, real-time gaming, multi-person video calls, autonomous driving, augmented reality, tactile Internet, virtual reality, home automation, robotics, and aerial drones, to name a few. All of these use cases and others are contemplated in this article.

[0067] Figure 1A An exemplary communication system 100 in which the systems, methods, and apparatus described and claimed herein may be used is illustrated. The communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, 102e, 102f, and / or 102g, generally or collectively referred to as WTRUs 102. The communication system 100 may include a radio access network (RAN) 103 / 104 / 105 / 103b / 104b / 105b, a core network 106 / 107 / 109, a public switched telephone network (PSTN) 108, the Internet 110, other networks 112, and network services 113. 113. The network services 113 may include, for example, a V2X server, a V2X function, a ProSe server, a ProSe function, IoT services, video streaming, and / or edge computing, etc.

[0068] It should be appreciated that the embodiments disclosed herein may be used with any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102 may be any type of device or apparatus configured to operate and / or communicate in a wireless environment. Figure 1A In the example of Figures 1A-1E. It should be understood that, for various use cases contemplated for wireless communication, each WTRU may include or be included in any type of device or apparatus configured to send and / or receive wireless signals, including, by way of example only, a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smart phone, a laptop, a tablet, a netbook, a notebook computer, a personal computer, a wireless sensor, a consumer electronic product, a wearable device (such as a smart watch or smart clothing), a medical or e-health device, a robot, an industrial equipment, a drone, a vehicle such as a car, bus or truck, a train, or an airplane, etc.

[0069] The communication system 100 may also include a base station 114a and a base station 114b. Figure 1A In the example of FIG. 1 , each base station 114 a and 114 b is depicted as a single element. In practice, the base stations 114 a and 114 b may include any number of interconnected base stations and / or network elements. The base station 114 a may be any type of device configured to wirelessly interface with at least one of the WTRUs 102 a, 102 b, and 102 c to facilitate access to one or more communication networks, such as the core network 106 / 107 / 109, the Internet 110, network services 113, and / or other networks 112. Similarly, the base station 114 b may be any type of device configured to interface wired and / or wirelessly with at least one of the remote radio heads (RRHs) 118 a, 118 b, the transmit and receive points (TRPs) 119 a, 119 b, and / or the roadside units (RSUs) 120 a and 120 b to facilitate access to one or more communication networks, such as the core network 106 / 107 / 109, the Internet 110, other networks 112, and / or network services 113. The RRHs 118 a, 118 b may be any type of device configured to interface wirelessly with at least one of the WTRUs 102, such as the WTRU 102 c, to facilitate access to one or more communication networks, such as the core network 106 / 107 / 109, the Internet 110, the network services 113, and / or the other networks 112.

[0070] The TRPs 119a, 119b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102d to facilitate access to one or more communication networks, such as the core network 106 / 107 / 109, the Internet 110, network services 113, and / or other networks 112. The RSUs 120a and 120b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102e or 102f to facilitate access to one or more communication networks, such as the core network 106 / 107 / 109, the Internet 110, other networks 112, and / or network services 113. By way of example, the base stations 114a, 114b may be base transceiver stations (BTSs), Node-Bs, eNode Bs, Home Node Bs, Home eNode Bs, next generation Node-Bs (gNode Bs), satellites, site controllers, access points (APs), wireless routers, and the like.

[0071] The base station 114a may be part of the RAN 103 / 104 / 105, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. Similarly, the base station 114b may be part of the RAN 103b / 104b / 105b, which may also include other base stations and / or network elements (not shown), such as a BSC, an RNC, a relay node, etc. The base station 114a may be configured to send and / or receive wireless signals within a specific geographic area, which may be referred to as a cell (not shown). Similarly, the base station 114b may be configured to send and / or receive wired and / or wireless signals within a specific geographic area, which may be referred to as a cell (not shown). The cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, for example, the base station 114a may include three transceivers, eg, one transceiver for each sector of the cell. The base station 114a may employ multiple-input multiple-output (MIMO) technology and thus, for example, may use multiple transceivers for each sector of the cell.

[0072] The base station 114a may communicate with one or more of the WTRUs 102a, 102b, 102c, and 102g over an air interface 115 / 116 / 117, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, cmWave, mmWave, etc.). The air interface 115 / 116 / 117 may be established using any suitable radio access technology (RAT).

[0073] The base station 114b may communicate with one or more of the RRHs 118a and 118b, the TRPs 119a and 119b, and / or the RSUs 120a and 120b via a wired or air interface 115b / 116b / 117b, which may be any suitable wired (e.g., cable, fiber optic, etc.) or wireless communication link (e.g., RF, microwave, IR, UV, visible light, cmWave, mmWave, etc.). The air interface 115b / 116b / 117b may be established using any suitable RAT.

[0074] The RRHs 118a, 118b, the TRPs 119a, 119b and / or the RSUs 120a, 120b may communicate with one or more of the WTRUs 102c, 102d, 102e, 102f via an air interface 115c / 116c / 117c, which may be any suitable wireless communication link (e.g., RF, microwave, IR, ultraviolet UV, visible light, cmWave, mmWave, etc.). The air interface 115c / 116c / 117c may be established using any suitable RAT.

[0075] The WTRUs 102 may communicate with each other via a direct air interface 115d / 116d / 117d, such as a sidelink communication, and the air interface 115d / 116d / 117d may be any suitable wireless communication link (e.g., RF, microwave, IR, ultraviolet UV, visible light, cmWave, mmWave, etc.). The air interface 115d / 116d / 117d may be established using any suitable RAT.

[0076] The communication system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 103 / 104 / 105 and the WTRUs 102a, 102b, 102c, or the RRHs 118a, 118b, TRPs 119a, 119b and / or RSUs 120a and 120b in the RAN 103b / 104b / 105b and the WTRUs 102c, 102d, 102e, and 102f may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interfaces 115 / 116 / 117 and / or 115c / 116c / 117c, respectively. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink Packet Access (HSDPA) and / or High Speed ​​Uplink Packet Access (HSUPA).

[0077] The base station 114a in the RAN 103 / 104 / 105 and the WTRUs 102a, 102b, 102c and 102g, or the RRHs 118a and 118b, TRPs 119a and 119b and / or RSUs 120a and 120b and the WTRUs 102c and 102d in the RAN 103b / 104b / 105b may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish an air interface 115 / 116 / 117 or 115c / 116c / 117c, respectively, using, for example, Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A). The air interface 115 / 116 / 117 or 115c / 116c / 117c may implement 3GPP NR technology. LTE and LTE-A technologies may include LTE D2D and / or V2X technologies and interfaces (such as sidelink communications, etc.). Similarly, 3GPP NR technologies may include NR V2X technologies and interfaces (such as sidelink communications, etc.).

[0078] The base station 114a in the RAN 103 / 104 / 105 and the WTRUs 102a, 102b, 102c, and 102g, or the RRHs 118a and 118b, the RPs 119a and 119b, and / or the RSUs 120a and 120b and the WTRUs 102c, 102d, 102e, and 102f in the RAN 103b / 104b / 105b may implement a radio technology such as IEEE 802.16 (e.g., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 IX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE), GSM EDGE(GERAN) etc.

[0079] Figure 1A The base station 114c in the example may be, for example, a wireless router, a Home Node B, a Home eNode B, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a business location, a home, a vehicle, a train, an airplane, a satellite, a factory, a campus, and the like. The base station 114c and the WTRU 102, such as the WTRU 102e, may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). Similarly, the base station 114c and the WTRU 102, such as the WTRU 102d, may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). The base station 114c and the WTRU 102, such as the WTRU 102e, may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, NR, etc.) to establish a pico cell or a femto cell. As Figure 1A As shown in FIG, the base station 114c may have a direct connection to the Internet 110. Thus, the base station 114c may not be required to access the Internet 110 via the core network 106 / 107 / 109.

[0080] The RAN 103 / 104 / 105 and / or the RAN 103b / 104b / 105b may be in communication with a core network 106 / 107 / 109, which may be any type of network configured to provide voice, data, messaging, authorization and authentication, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102. For example, the core network 106 / 107 / 109 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, packet data network connectivity, Ethernet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication.

[0081] Although not in Figure 1A 105b and / or the core network 106 / 107 / 109 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 103 / 104 / 105 and / or the RAN 103b / 104b / 105b or a different RAT. For example, in addition to being connected to the RAN 103 / 104 / 105 and / or the RAN 103b / 104b / 105b, which may utilize an E-UTRA radio technology, the core network 106 / 107 / 109 may also be in communication with another RAN (not shown) that employs a GSM or NR radio technology.

[0082] The core network 106 / 107 / 109 may also serve as a gateway for the WTRU 102 to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and the Internet Protocol (IP) in the TCP / IP Internet protocol suite. Other networks 112 may include wired or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include any type of packet data network (e.g., IEEE 802.3 Ethernet) or another core network connected to one or more RANs, which may use the same RAT as the RAN 103 / 104 / 105 and / or the RAN 103b / 104b / 105b or a different RAT.

[0083] Some or all of the WTRUs 102a, 102b, 102c, 102d, 102e, and 102f in the communication system 100 may include multi-mode capabilities, e.g., the WTRUs 102a, 102b, 102c, 102d, 102e, and 102f may include multiple transceivers for communicating with different wireless networks via different wireless links. Figure 1A The WTRU 102g shown in FIG. 1 may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114c, which may employ an IEEE 802 radio technology.

[0084] Although not in Figure 1A 106 / 107 / 109. It is shown in the figure, however, it is appreciated that the user equipment can establish a wired connection to the gateway. The gateway can be a residential gateway (RG). The RG can provide connectivity with the core network 106 / 107 / 109. It is appreciated that many of the concepts contained herein can be equally applied to a UE that is a WTRU and a UE that uses a wired connection to connect to the network. For example, the concepts applied to the wireless interfaces 115, 116, 117 and 115c / 116c / 117c can be equally applied to wired connections.

[0085] Figure 1B 1 is a system diagram illustrating the RAN 103 and the core network 106. As described above, the RAN 103 may employ UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 115. The RAN 103 may also be in communication with the core network 106. Figure 1B As shown in FIG. 1 , the RAN 103 may include Node-Bs 140a, 140b, and 140c, which may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 115. The Node-Bs 140a, 140b, and 140c may each be associated with a particular cell (not shown) within the RAN 103. It should be appreciated that the RAN 103 may also include RNCs 142a, 142b. The RAN 103 may include any number of Node-Bs and radio network controllers (RNCs).

[0086] like Figure 1BAs shown in , Node-B 140a, 140b can communicate with RNC 142a. In addition, Node-B 140c can communicate with RNC 142b. Node-B 140a, 140b and 140c can communicate with corresponding RNC 142a and 142b via Iub interface. RNC 142a and 142b can communicate with each other via Iur interface. Each of RNC 142a and 142b can be configured to control the corresponding Node-B 140a, 140b and 140c connected thereto. In addition, each of RNC 142a and 142b can be configured to perform or support other functions, such as outer loop power control, load control, admission control, packet scheduling, handover control, macro diversity, security functions, data encryption, etc.

[0087] Figure 1B The core network 106 shown in FIG. 1 may include a media gateway (MGW) 144, a mobile switching center (MSC) 146, a serving GPRS support node (SGSN) 148, and / or a gateway GPRS support node (GGSN) 150. Although each of the above elements is depicted as part of the core network 106, it is appreciated that any of these elements may be owned and / or operated by an entity other than the core network operator.

[0088] The RNC 142a in the RAN 103 may be connected to the MSC 146 in the core network 106 via an IuCS interface. The MSC 146 may be connected to the MGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102a, 102b, and 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, and 102c and traditional land-line communications devices.

[0089] The RNC 142a in the RAN 103 may also be connected to the SGSN 148 in the core network 106 via an IuPS interface. The SGSN 148 may be connected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide the WTRUs 102a, 102b, and 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, and 102c and IP-enabled devices.

[0090] The core network 106 may also be connected to other networks 112, which may include other wired or wireless networks owned and / or operated by other service providers.

[0091] Figure 1C1 is a system diagram of an example RAN 104 and a core network 107. As described above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 116. The RAN 104 may also be in communication with the core network 107.

[0092] The RAN 104 may include eNode-Bs 160a, 160b, and 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs. The eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. For example, the eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0093] Each of the eNode-Bs 160a, 160b, and 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink and / or downlink, etc. Figure 1C As shown in FIG. , eNode-Bs 160a , 160b , and 160c may communicate with each other via an X2 interface.

[0094] Figure 1C The core network 107 shown in FIG. 1 may include a mobility management gateway (MME) 162, a serving gateway 164, and a packet data network (PDN) gateway 166. Although each of the above elements is depicted as part of the core network 107, it is appreciated that any of these elements may be owned and / or operated by an entity other than the core network operator.

[0095] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, and 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, and 102c, etc. The MME 162 may also provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM or WCDMA.

[0096] The serving gateway 164 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an S1 interface. The serving gateway 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, and 102c. The serving gateway 164 may also perform other functions, such as anchoring the user plane during inter-eNode B handovers, triggering paging when downlink data is available for the WTRUs 102a, 102b, and 102c, managing and storing the contexts of the WTRUs 102a, 102b, and 102c, and the like.

[0097] The serving gateway 164 may also be connected to the PDN gateway 166, which may provide the WTRUs 102a, 102b, and 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0098] The core network 107 may facilitate communications with other networks. For example, the core network 107 may provide the WTRUs 102a, 102b, and 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, and 102c and traditional land-line communications devices. For example, the core network 107 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the core network 107 and the PSTN 108. In addition, the core network 107 may provide the WTRUs 102a, 102b, and 102c with access to the networks 112, which may include other wired or wireless networks owned and / or operated by other service providers.

[0099] Figure 1D 1 is a system diagram of an example RAN 105 and a core network 109. The RAN 105 may employ NR radio technology to communicate with the WTRUs 102a and 102b over the air interface 117. The RAN 105 may also be in communication with the core network 109. A non-3GPP interworking function (N3IWF) 199 may employ non-3GPP radio technology to communicate with the WTRU 102c over the air interface 198. The N3IWF 199 may also be in communication with the core network 109.

[0100] The RAN 105 may include gNode-Bs 180a and 180b. It is to be appreciated that the RAN 105 may include any number of gNode-Bs. The gNode-Bs 180a and 180b may each include one or more transceivers for communicating with the WTRUs 102a and 102b over the air interface 117. When an integrated access and backhaul connection is used, the same air interface may be used between the WTRUs and the gNode-Bs, which may be a core network 109 via one or more gNBs. The gNode-Bs 180a and 180b may implement MIMO, MU-MIMO, and / or digital beamforming techniques. Thus, the gNode-B 180a, for example, may use multiple antennas to send wireless signals to the WTRU 102a and receive wireless signals from the WTRU 102a. It is to be appreciated that the RAN 105 may employ other types of base stations, such as an eNode-B. It is also to be appreciated that the RAN 105 may employ more than one type of base station. For example, the RAN may employ both eNode-Bs and gNode-Bs.

[0101] The N3IWF 199 may include a non-3GPP access point 180c. It will be appreciated that the N3IWF 199 may include any number of non-3GPP access points. The non-3GPP access point 180c may include one or more transceivers for communicating with the WTRU 102c over the air interface 198. The non-3GPP access point 180c may communicate with the WTRU 102c over the air interface 198 using the 802.11 protocol.

[0102] The gNode-Bs 180a and 180b may each be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in uplink or downlink, etc. Figure 1D As shown in FIG. , gNode-Bs 180a and 180b may communicate with each other, for example, via an Xn interface.

[0103] Figure 1D The core network 109 shown in the figure can be a 5G core network (5GC). The core network 109 can provide numerous communication services to customers interconnected by a radio access network. The core network 109 includes multiple entities that perform the functions of the core network. The terms "core network entity" or "network function" as used herein refer to any entity that performs one or more functions of the core network. It should be understood that such a core network entity can be a logical entity implemented in the form of computer executable instructions (software) stored in a device configured for wireless and / or network communications, or a computer system, such as Figure 1Gin a memory of the system shown in the diagram and executed on a processor thereof.

[0104] exist Figure 1D In the example of , the 5G core network 109 may include access and mobility management function (AMF) 172, session management function (SMF) 174, user plane function (UPF) 176a and 176b, user data management function (UDM) 197, authentication server function (AUSF) 190, network open function (NEF) 196, policy control function (PCF) 184, non-3GPP interworking function (N3IWF) 199, user data repository (UDR) 178. Although each of the above elements is depicted as part of the 5G core network 109, it is to be appreciated that any of these elements may be owned and / or operated by an entity other than the core network operator. It is also to be appreciated that the 5G core network may not consist of all of these elements, may consist of additional elements, and may consist of multiple instances of each of these elements. Figure 1D This indicates that the network functions are directly connected to each other, but it is appreciated that they may communicate via a routing agent, such as the diameter routing agent, or a message bus.

[0105] exist Figure 1D In the example of , the connectivity between network functions is achieved via a set of interfaces or reference points. It is to be appreciated that network functions can be simulated, described or implemented as a set of services that are invoked or called by other network functions or services. The invocation of network function services can be achieved via direct connections between network functions, exchange of messages on a message bus, calling software functions, etc.

[0106] The AMF 172 may be connected to the RAN 105 via an N2 interface and may serve as a control node. For example, the AMF 172 may be responsible for registration management, connection management, reachability management, access authentication, access authorization. The AMF may be responsible for forwarding user plane tunnel configuration information to the RAN 105 via the N2 interface. The AMF 172 may receive user plane tunnel configuration information from the SMF via the N11 interface. The AMF 172 may generally route and forward NAS packets to and from the WTRUs 102a, 102b, and 102c via the N1 interface. The N1 interface is not used in Figure 1D Shown in.

[0107] The SMF 174 may be connected to the AMF 172 via the N11 interface. Similarly, the SMF may be connected to the PCF 184 via the N7 interface and to the UPFs 176a and 176b via the N4 interface. The SMF 174 may serve as a control node. For example, the SMF 174 may be responsible for session management, IP address allocation for the WTRUs 102a, 102b, and 102c, management and configuration of traffic steering rules in the UPFs 176a and 176b, and generation of downlink data notifications to the AMF 172.

[0108] The UPF 176a and UPF 176b may provide the WTRUs 102a, 102b, and 102c with access to a packet data network (PDN), such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, and 102c and other devices. The UPF 176a and UPF 176b may also provide the WTRUs 102a, 102b, and 102c with access to other types of packet data networks. For example, the other network 112 may be an Ethernet network or any type of network that switches data packets. The UPF 176a and UPF 176b may receive traffic steering rules from the SMF 174 via an N4 interface. The UPF 176a and UPF 176b may provide access to a packet data network by connecting to the packet data network using an N6 interface, or by connecting to each other or to other UPFs via an N9 interface. In addition to providing access to the packet data network, UPF 176 may also be responsible for packet routing and forwarding, policy rule enforcement, quality of service processing for user plane traffic, and downlink packet buffering.

[0109] The AMF 172 may also be connected to the N3IWF 199, for example, via an N2 interface. The N3IWF facilitates connectivity between, for example, the WTRU 102c and the 5G Core Network 170, via a radio interface technology not defined by 3GPP. The AMF may interact with the N3IWF 199 in the same or similar manner as it interacts with the RAN 105.

[0110] PCF 184 may be connected to SMF 174 via an N7 interface, to AMF 172 via an N15 interface, and to application function (AF) 188 via an N5 interface. The N15 and N5 interfaces are not Figure 1D1. The PCF 184 may provide policy rules to control plane nodes such as the AMF 172 and the SMF 174, thereby allowing the control plane nodes to implement these rules. The PCF 184 may send the policy to the AMF 172 for the WTRUs 102a, 102b, and 102c so that the AMF may deliver the policy to the WTRUs 102a, 102b, and 102c via the N1 interface. The policy may then be implemented or applied at the WTRUs 102a, 102b, and 102c.

[0111] The UDR 178 may serve as a repository for authentication credentials and subscription information. The UDR may be connected to a network function so that the network function can add data to, read data from, and modify data in the repository. For example, the UDR 178 may be connected to the PCF 184 via an N36 interface. Similarly, the UDR 178 may be connected to the NEF 196 via an N37 interface, and the UDR 178 may be connected to the UDM 197 via an N35 interface.

[0112] The UDM 197 may serve as an interface between the UDR 178 and other network functions. The UDM 197 may authorize network functions to access the UDR 178. For example, the UDM 197 may be connected to the AMF 172 via the N8 interface, and the UDM 197 may be connected to the SMF 174 via the N10 interface. Similarly, the UDM 197 may be connected to the AUSF 190 via the N13 interface. The UDR 178 and the UDM 197 may be tightly integrated.

[0113] AUSF 190 performs authentication-related operations, is connected to UDM 178 via an N13 interface, and is connected to AMF 172 via an N12 interface.

[0114] NEF 196 opens capabilities and services in 5G core network 109 to application function (AF) 188. The opening can occur on the N33 API interface. NEF can be connected to AF 188 via the N33 interface, and it can be connected to other network functions to open capabilities and services of 5G core network 109.

[0115] The application function 188 may interact with the network functions in the 5G core network 109. The interaction between the application function 188 and the network functions may occur via a direct interface or may occur via the NEF 196. The application function 188 may be considered part of the 5G core network 109 or may be external to the 5G core network 109 and deployed by an enterprise having a business relationship with a mobile network operator.

[0116] Network slicing is a mechanism that can be used by mobile network operators to support one or more 'virtual' core networks behind the operator's air interface. This involves 'slicing' the core network into one or more virtual networks to support different RANs or different service types running across a single RAN. Network slicing enables operators to create customized networks to provide optimized solutions for different market scenarios with diverse requirements in terms of functionality, performance and isolation, for example.

[0117] 3GPP has designed the 5G core network to support network slicing. Network slicing is a good tool that network operators can use to support a diverse set of 5G use cases (e.g., massive IoT, critical communications, V2X, and enhanced mobile broadband) that require very diverse and sometimes extreme requirements. Without the use of network slicing technology, when each use case has its own specific set of performance, scalability, and availability requirements, it is likely that the network architecture will not be flexible and scalable enough to effectively support a wider range of use cases. In addition, the introduction of new network services should be made more efficient.

[0118] See again Figure 1D In a network slicing scenario, the WTRU 102a, 102b, or 102c may be connected to the AMF 172 via the N1 interface. The AMF may be logically part of one or more slices. The AMF 172 may coordinate the connection or communication of the WTRU 102a, 102b, or 102c with one or more UPFs 176a and 176b, SMF 174, and other network functions. Each of the UPFs 176a and 176b, the SMF 174, and other network functions may be part of the same slice or different slices. When they are part of different slices, they may be isolated from each other in terms of the different computing resources, security credentials, etc. that they may utilize.

[0119] The core network 109 may facilitate communications with other networks. For example, the core network 109 may include an IP gateway, such as an IP Multimedia Subsystem (IMS) server, that serves as an interface between the 5G core network 109 and the PSTN 108, or may communicate with the IP gateway. For example, the core network 109 may include a short message service (SMS) service center that facilitates communications via a short message service, or may communicate with the short message service (SMS) service center. For example, the 5G core network 109 may facilitate the exchange of non-IP data packets between the WTRUs 102a, 102b, and 102c and a server or application function 188. In addition, the core network 170 may provide the WTRUs 102a, 102b, and 102c with access to the networks 112, which may include other wired or wireless networks owned or operated by other service providers.

[0120] Described in this article and Figure 1A , 1C The core network entities illustrated in 1D and 1E are identified using the names given to these entities in certain existing 3GPP specifications, but it should be understood that in the future, these entities and functions may be identified with other names, and in future specifications released by 3GPP, including future 3GPP NR specifications, some entities or functions may be combined. Figure 1A , 1B The specific network entities and functions described and illustrated in 1C, 1D and 1E are provided as examples only, and it should be understood that the subject matter disclosed and claimed herein may be implemented or realized in any similar communication system (whether currently defined or defined in the future).

[0121] Figure 1E The diagram illustrates an example communication system 111 in which the systems, methods, and apparatus described herein may be used. The communication system 111 may include wireless transmit / receive units (WTRUs) A, B, C, D, E, F, a base station gNB 121, a V2X server 124, and roadside units (RSUs) 123a and 123b. In practice, the concepts presented herein may be applied to any number of WTRUs, base stations gNBs, V2X networks, and / or other network elements. One or several or all of the WTRUs A, B, C, D, E, and F may be outside the range of the access network coverage 131. WTRUs A, B, and C form a V2X group, where WTRU A is the group leader and WTRUs B and C are group members.

[0122] WTRUs A, B, C, D, E, and F may communicate with each other via the gNB 121 over the Uu interface 129 if they are within the access network coverage 131. Figure 1E In the example of FIG. 1 , WTRUs B and F are shown within access network coverage 131. WTRUs A, B, C, D, E, and F may communicate directly with each other via a sidelink interface (e.g., PC5 or NR PC5), such as interfaces 125a, 125b, or 128, whether they are within or outside access network coverage 131. For example, in Figure 1E In the example of , WTRU D outside the access network coverage 131 communicates with WTRU F within the coverage 131.

[0123] WTRUs A, B, C, D, E, and F may communicate with the RSU 123a or 123b via the vehicle-to-network (V2N) 133 or the sidelink interface 125b. WTRUs A, B, C, D, E, and F may communicate with the V2X server 124 via the vehicle-to-infrastructure (V2I) interface 127. WTRUs A, B, C, D, E, and F may communicate with another UE via the vehicle-to-pedestrian (V2P) interface 128.

[0124] Figure 1F is an example device or apparatus (such as Figure 1A , 1B , 1C, 1D or 1E WTRU 102). Figure 1F As shown in the example WTRU 102, the example WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad / indicator 128, a non-removable memory 130, a removable memory 132, a power supply 134, a global positioning system (GPS) chipset 136, and other peripherals 138. It is to be appreciated that the WTRU 102 may include any sub-combination of the above elements. In addition, the base stations 114a and 114b and / or the base stations 114a and 114b may represent nodes such as, but not limited to, a transceiver station (BTS), a Node-B, a site controller, an access point (AP), a home node-B, an evolved home node-B (eNodeB), a home evolved node-B (HeNB), a home evolved node-B gateway, a next generation node-B (gNode-B), and a proxy node, etc., and may include Figure 1F Some or all of the elements depicted in and described herein.

[0125] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1F The processor 118 and the transceiver 120 are depicted as separate components, although it is appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0126] The transmit / receive element 122 of the UE may be configured to transmit data to a base station (eg, Figure 1A 114a) to send signals to or from a base station (e.g., Figure 1A The base station 114a) receives a signal, or sends a signal to another UE or receives a signal from another UE through the air interface 115d / 116d / 117d. For example, the send / receive element 122 can be an antenna configured to send and / or receive RF signals. The send / receive element 122 can be, for example, a transmitter / detector configured to send and / or receive IR, UV or visible light signals. The send / receive element 122 can be configured to send and receive both RF signals and optical signals. It should be appreciated that the send / receive element 122 can be configured to send and / or receive any combination of wireless signals or wired signals.

[0127] In addition, although the transmit / receive element 122 is Figure 1F Although depicted as a single element in the figure, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 115 / 116 / 117.

[0128] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As described above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11 or NR and E-UTRA, or to communicate using the same RAT via multiple beams to different RRHs, TRPs, RSUs, or nodes.

[0129] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad / indicator 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad / indicator 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. The processor 118 may access information from, and store data in, a memory that is not physically located in the WTRU 102, such as a memory hosted on a server in a cloud or edge computing platform or in a home computer (not shown).

[0130] The processor 118 may obtain power from the power source 134 and may be configured to distribute power to and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries, solar cells, fuel cells, etc.

[0131] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 115 / 116 / 117 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method.

[0132] The processor 118 may also be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include various sensors such as accelerometers, biometric (e.g., fingerprint) sensors, electronic compasses, satellite transceivers, digital cameras (for photos or videos), universal serial bus (USB) ports or other interconnect interfaces, vibration devices, television transceivers, hands-free headsets, modules, FM radio units, digital music players, media players, video game player modules, Internet browsers, etc.

[0133] The WTRU 102 may be included in other devices or apparatuses, such as sensors, consumer electronics, wearable devices such as smart watches or smart clothing, medical or e-health devices, robots, industrial equipment, drones, vehicles such as cars, trucks, trains, or airplanes. The WTRU 102 may be connected to other components, modules, or systems of such devices or apparatuses via one or more interconnect interfaces, such as an interconnect interface that may include one of the peripheral devices 138.

[0134] Figure 1G is a block diagram of an example computing system 90, which may include Figure 1A , 1C , 1D and 1E, such as certain nodes or functional entities in the RAN 103 / 104 / 105, the core network 106 / 107 / 109, the PSTN 108, the Internet 110, other networks 112 or network services 113. The computing system 90 may include a computer or a server and may be primarily controlled by computer-readable instructions, which may be in the form of software, regardless of where or how such software is stored or accessed. Such computer-readable instructions may be executed within the processor 91 to enable the computing system 90 to work. The processor 91 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 91 may perform signal encoding, data processing, power control, input / output processing, and / or any other function that enables the computing system 90 to operate in a communication network. Coprocessor 81 is an optional processor distinct from main processor 91 that may perform additional functions or assist processor 91. Processor 91 and / or coprocessor 81 may receive, generate, and process data related to the methods and apparatus disclosed herein.

[0135] In operation, processor 91 retrieves, decodes and executes instructions and transfers information to and from other resources via the computing system's main data transfer path, system bus 80. Such a system bus connects components in computing system 90 and defines a medium for data exchange. System bus 80 typically includes data lines for sending data, address lines for sending addresses, and control lines for sending interrupts and for operating the bus. An example of such a system bus 80 is a PCI (Peripheral Component Interconnect) bus.

[0136] The memory coupled to the system bus 80 includes a random access memory (RAM) 82 and a read-only memory (ROM) 93. Such memory includes circuits that allow information to be stored and retrieved. ROM 93 generally contains stored data that is not easily modified. The data stored in RAM 82 can be read or changed by a processor 91 or other hardware device. Access to RAM 82 and / or ROM 93 can be controlled by a memory controller 92. The memory controller 92 can provide an address translation function that converts a virtual address into a physical address when an instruction is executed. The memory controller 92 can also provide a memory protection function that isolates processes within the system and isolates system processes from user processes. Thus, a program running in the first mode can only access memory mapped by its own process virtual address space; unless memory sharing between processes is set, it cannot access memory within the virtual address space of another process.

[0137] In addition, the computing system 90 may include a peripheral device controller 83 , which is responsible for communicating instructions from the processor 91 to peripheral devices, such as a printer 94 , a keyboard 84 , a mouse 95 , and a disk drive 85 .

[0138] The display 86 controlled by the display controller 96 is used to display the visual output generated by the computing system 90. Such visual output may include text, graphics, animated graphics, and video. The visual output may be provided in the form of a graphical user interface (GUI). The display 86 may be implemented with a CRT-based video display, an LCD-based flat panel display, a gas plasma-based flat panel display, or a touch panel. The display controller 96 includes the electronic components required to generate the video signal sent to the display 86.

[0139] In addition, the computing system 90 may include a communication network or device that can be used to connect the computing system 90 to an external communication network or device, such as Figure 1A , 1B, RAN 103 / 104 / 105 of 1C, 1D and 1E, core network 106 / 107 / 109, PSTN 108, Internet 110, WTRU 102 or other network 112 to enable the computing system 90 to communicate with other nodes or functional entities of these networks, such as communication circuits such as wireless or wired network adapter 97. The communication circuits can be used alone or in combination with the processor 91 to perform the sending and receiving steps of certain devices, nodes or functional entities described herein.

[0140] It should be understood that any or all of the devices, systems, methods, and processes described herein may be embodied in the form of computer executable instructions (e.g., program code) stored on a computer-readable storage medium, which, when executed by a processor, such as processor 118 or 91, causes the processor to perform and / or implement the systems, methods, and processes described herein. Specifically, any steps, operations, or functions described herein may be implemented in the form of such computer executable instructions executed on a processor of a device or computing system configured for wireless and / or wired network communications. Computer-readable storage media include volatile and non-volatile, removable and non-removable media implemented in any non-temporary (e.g., tangible or physical) method or technology for storage of information, although such computer-readable storage media do not include signals. Computer-readable storage media include (but are not limited to) RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, cassettes, magnetic tape, magnetic disk storage or other magnetic storage, or any other tangible or physical medium that can be used to store the desired information and can be accessed by a computing system.

[0141] Sub-6 GHz operation in unlicensed bands in LTE and NR

[0142] With the introduction of LTE-LAA, LTE-based standards enable LTE-based access to unlicensed bands in the sub-6 GHz range. LAA enables DL access to SCells on unlicensed bands aggregated with licensed band PCells. Additionally, eLAA enables UL access, while feLAA introduces autonomous UL access on unlicensed bands. New Radio (NR) introduces NR-based DL and UL operations in the sub-6 GHz range and supports standalone operations in unlicensed spectrum.

[0143] Channel Sensing in LTE and NR

[0144] In the sub-6GHz range, omnidirectional or quasi-omnidirectional channel sensing is used. When a node senses a channel and determines that the channel is idle, the node continues to occupy the channel by transmitting in an omnidirectional or directional manner for a duration called COT. After the transmission is completed or the maximum channel occupation time (MCOT) is reached, the node releases the channel so that other devices can occupy the channel.

[0145] A node may also allow other nodes to occupy its acquired channel through a mechanism called COT sharing. Here, one node obtains channel access through a CAT4 LBT procedure and enables a second node to use a portion of its COT without the need for channel sensing such as with a CAT1 procedure or with short duration sensing (25 μs) such as a CAT2 LBT procedure. Figure 2A Diagram illustrating COT acquisition after CAT4 LBT. Figure 2B The diagram illustrates CAT2 LBT and UL transmissions performed by the UE in the COT acquired by the gNB.

[0146] Sub-band aggregation in sub-6 GHz unlicensed spectrum

[0147] It is desirable to aggregate multiple adjacent subbands in a single wideband carrier to improve spectrum utilization by using spectrum that would otherwise be allocated as a guard band between subbands. This provides an improvement over carrier aggregation. In sub-6GHz, 10MHz or 20MHz subbands can be synthesized into a single carrier. The number of available subbands typically varies in a given channel access opportunity. Thus, a device obtains a COT on certain subbands in a channel access opportunity and can indicate the status of its COT and subband to devices in its network. In NR-U Rel.16, such indication can occur explicitly in a multicast manner via control signaling.

[0148] WiGiG

[0149] The IEEE 802.11ad and 802.11ay standards enable WiFi-like communications in the mmW range. PCP / AP and STA perform CSMA / CA for channel access during the contention-based access period. They support physical carrier sensing (a function provided by the physical layer through energy or preamble detection) and virtual carrier sensing (a function provided by the MAC layer through the RTS / CTS protocol and a timer mechanism using the Network Allocation Vector (NAV) timer). The NAV field in the MAC header of the RTS and CTS messages indicates in microseconds how long the channel is reserved by another station. During the timer time, the channel is considered busy. Thus, virtual carrier sensing limits the need for physical carrier sensing to save power.

[0150] NR operation in mmWave spectrum

[0151] The 37GHz and 60GHz bands are good candidates for unlicensed operation of cellular technologies in the mmW range. These spectra offer very large bandwidths and are attractive options for various use cases such as eMBB, mobile data offload, backhaul, short-range D2D, enterprise networks, private networks, etc. These frequencies support high antenna directivity and beamforming. However, the spectrum also poses many challenges - for wavelengths in the mmW range, high path loss and oxygen absorption make the coverage limited to a few hundred meters. Communications in these bands are mainly characterized by LOS transmissions and direct reflection paths.

[0152] Typical use cases identified for operation in these bands include eMBB, data offload, backhaul, factory applications, virtual networks, augmented reality / virtual reality, redundant network applications, IIOT, etc. Target deployment scenarios include indoor hotspots, dense urban areas, urban micro / macro cells, rural areas, factories, indoor D2D.

[0153] TRP and Multi-Panel Sending

[0154] Operation in the mmW range is expected to be achieved through phased array antennas and massive MIMO, providing beamforming between transmitter and receiver. The beams are expected to be highly directional to achieve sufficiently high SINR and range. It is also expected that multiple beams will be deployed in a typical network to ensure reliability and overcome blocking.

[0155] Multiple TRPs can be deployed to provide good spatial coverage. Figure 3A An example of multiple TRP communications is shown in Figure 1. For an ideal backhaul, such as point-to-point connections using fiber, the TRPs can be connected with very high throughput and very low latency. For non-ideal backhauls, such as mmW communications, microwave, and relay networks, there can be significant delays between TRPs.

[0156] The UE may also be equipped with multiple panels so that it can perform beamforming in multiple directions simultaneously. Figure 3B An example of multi-panel UE communication is shown in FIG.

[0157] Omnidirectional sensing versus directional sensing

[0158] Omnidirectional or quasi-omnidirectional sensing checks the channel availability in the spatial domain, i.e., a channel is considered idle if it is idle in the omnidirectional or quasi-omnidirectional space. This is a typical sensing mode in the sub-6GHz range. Devices using omnidirectional or quasi-omnidirectional sensing may only transmit directional and not fully require the spatial channel at a given time. This can limit spatial reuse, leading to exposed nodes and thus underutilization of the channel. For example, Figure 4A A non-ideal backhaul network is shown in . Here, the nodes perform omnidirectional sensing; thus, TRP2 senses TRP1's transmission to UE1 and does not transmit to UE2. Therefore, the UE is able to receive from multiple TRPs simultaneously through spatial discrimination, but the sensing mechanism limits simultaneous transmission to the UE.

[0159] Another disadvantage of omni-directional or quasi-omni-directional sensing is that the sensing range is limited compared to the directionality of the transmission. Therefore, a transmitter using omni-directional or quasi-omni-directional sensing may not have a good impression of the receiver's environment.

[0160] This makes directional sensing more attractive. Through this mechanism, multiple independent links can be operated simultaneously in different spatial directions, such as Figure 4B As shown in , where the TRP1-UE1 link and the TRP2-UE2 link operate in the same time and frequency resources, but they do not interfere with each other because their channels are spatially separated. Directional sensing is performed by using spatial domain filters with certain spatial characteristics (such as angular spread, azimuth and elevation orientation, and gain). The directionality and steering of the beam are obtained by analog (such as phased array) beamforming or digital beamforming or a combination of both.

[0161] However, directional sensing can cause a "hidden node" problem, as the transmitter may be deaf to the receiver's environment. Figure 4C In the example, TRP1 performs directional sensing and transmits to UE1. TRP2 also performs directional sensing and finds an idle channel, but its transmission to UE2 interferes with UE1. Thus, TRP2 is a hidden node of the TRP1-UE1 link.

[0162] Get a directional channel

[0163] In order to acquire a channel with directionality, a node must select an appropriate spatial domain filter for channel sensing or LBT. The choice of spatial filter may depend on network characteristics such as traffic load, node density, presence of other co-channel networks and technologies, spatial orientation of the intended receiver, type and amount of control and data to be sent. By managing the channel access of nodes via appropriate spatial filters, different spatial reuse factors can be achieved and throughput can be improved in unlicensed deployments.

[0164] Since the influencing factors can change over time, multiple spatial filters for LBT can be supported. Nodes can change the spatial filter used for LBT to achieve targeted spatial reuse or respond to changes in the network.

[0165] Generally, when a node performs LBT using a spatial domain filter L to obtain channel access, it can use a set of spatial filters {Di} to send data so that one or more of the following characteristics are met. The angular spread of the resulting main lobe (for all integer values ​​of i) is spatially contained within the main lobe of L in both azimuth and elevation. This can be evaluated in terms of the angular spread of the beam. The angular spread of Di does not exceed the angular spread of L.

[0166] Depend on The peak power in the resulting main lobe is shifted △i,m dB relative to the peak power in the main lobe of L. Figure 5 It shows that TRP uses spatial filter L to produce a wider beam and uses spatial filter Di to produce a narrower beam, so that the angular spread of the narrower beam is contained within the angular spread of L. Since the narrow beam has higher directivity, the peak of the narrow beam is higher than the peak of the wide beam by △i,m. The average power in the resulting side lobes is offset by △i,s dB relative to the average power in the side lobes of L. The relative power in the resulting side lobes is offset by Δi,r dB relative to the power in the main lobe of L. If L is an omnidirectional or quasi-omnidirectional filter, then {Di} may include beams in every possible spatial direction. The power constraints imposed by Δi,m or Δi,s or Δi,r ensure that highly directional transmission beams with a range significantly higher than L can be treated differently.

[0167] Once the device obtains channel access using the spatial filter L, it can transmit on the directional beam Di, which may have a longer range than the filter L. Transmission using Di may cause interference with another node because sensing using L may not sense the environment of the receiver. This is because the range of L is generally shorter than the range of Di. In order to solve the problem of the transmitter being deaf, it is proposed to exchange messages bidirectionally between the transmitter and the receiver to ensure that the channel is idle for both nodes. As a result, the transmitter can send CAI-T to the intended (one or more) receivers. The receiver responds to the transmitter with CAI-R. When a CAI-R is received indicating that the environment at the receiver is idle for reception, the transmitter can send control and data signals and / or additional information indicating channel reservation to the receiver. Before the COT of the transmitter, at the beginning of the COT of the transmitter, the exchange of CAI-T and CAI-R can be used as a handshake between devices. Below, we refer to the handshake process using CAI-T and CAI-R as FBLBT. We also refer to the COT obtained using directional filters as "directional COT".

[0168] Channel access process

[0169] According to another aspect of the present application, described below is a channel access procedure in which a gNB attempts channel access to communicate with a UE. Fig. 6A As shown in , the TRP and UE communicate using different spatial filters at different stages of the channel access and transmission process. Overlapping beams conceptually indicate that within a given COT, the angular spread of the transmit beam is contained within the angular spread of the LBT beam. The range and SINR of the LBT and transmit beams can vary depending on the degree of co-phasing of the antenna array elements.

[0170] refer to Figure 6B The following steps are described. The figure also shows the beams used in the different stages and can be compared with Fig. 6A The beams in are associated.

[0171] 1. The gNB selects a spatial filter L for LBT from the set {F} of possible LBT spatial filters. The gNB performs channel sensing using filter L. This can be a random backoff within the contention window, similar to CAT4 LBT with a specific channel access priority level. For example, this can be applied in a load-based equipment (LBE) mode of operation. Alternatively, the channel sensing can be similar to CAT2 LBT with a fixed sensing period. For example, this can be applied in a frame-based equipment (FBE) mode of operation, sensing in an idle period before a fixed frame period (FFP).

[0172] 2. Upon detecting an idle channel, the gNB obtains a directional COT in the direction of the spatial filter L. Once obtained through the LBT filter L, the gNB can operate in this COT using a set of spatial filters {D} (e.g., for transmission, reception, and sensing) that meet the requirements for operating on this channel. {D} may also include the spatial filter L. During the COT, the gNB can use the spatial filters in {D} for sensing or transmission. The gNB sends CAI-T to the UE using the spatial filter Di∈{D} (Di belongs to the set {D}). In general, the gNB can send CAI-T on multiple beams using multiple filters from {D}. This may be useful for simultaneously addressing multiple UEs on different beams within the same COT.

[0173] 3. Subsequently or simultaneously, the UE selects a spatial filter Rm and performs short channel sensing, such as CAT2-based sensing. Rm∈{R}, where {R} is a set of spatial filters that can be used in response to CAI-T sent on the shared COT obtained using the LBT spatial filter L. Rm can also depend on the spatial filter Rn that will be used to send CAI-R in the next step.

[0174] 4. When the channel is determined to be idle, the UE sends a CAI-R on Rn, indicating that it is ready to receive signals from the gNB. The UE can set Rm = Rn. In other words, the UE can use the same filter used to transmit to the gNB for sensing, reducing the sensing burden on the UE.

[0175] 5. The gNB senses the channel using short duration sensing such as CAT2 sensing using one or more spatial filters Dj, where Dj∈{D}.

[0176] 6. Upon finding that the channel is idle, the gNB uses one or more spatial filters in {D} to send one or more of COT information, control information, data, and channel reservation (CR) signaling. In this example, the gNB transmits on two beams Dk and Dl. The channel reservation signal itself can carry COT information, which includes the expected time of channel occupancy, the subbands occupied by the channel, and spatial information about channel occupancy.

[0177] 7. The UE receives these signals. In embodiments where the UE must send a response, the UE uses a spatial filter Rp∈{R} for short duration sensing, such as CAT2 LBT. The selection of a suitable spatial filter Rp may depend on the spatial filter Rq employed by the UE for transmission back to the gNB.

[0178] 8. Upon finding that the channel is idle, the UE sends data and / or control information using the spatial filter Rq.

[0179] 9. Once the communication is completed, the gNB releases the channel by stopping transmission on the channel.

[0180] According to the above embodiment, the TRP performs channel access and shares its information with the UE. However, it is conceivable that the UE can initiate a COT and share its information with the TRP or other UEs on the side link.

[0181] Figure 7 The timeline of channel sensing, handshake and transmission between gNB and UE in COT obtained by gNB is shown in FIG. Fig. 6A When the TRP in the example of ) obtains channel access after LBT using the spatial filter L, it can send CAI-R to multiple other nodes, such as UE1, UE2 and UE3, such as Figure 8 As shown in . TRP uses spatial filter D1 to send CAI-T1 to UE1 and UE2, and uses spatial filter D2 to send CAI-T2 to UE3. D1 and D2 meet the transmission requirements within the directional COT obtained using spatial filter L.

[0182] CAI-T1 and CAI-T2 transmission can be sent in SDM or TDM mode. CAI-T can be sent as group common control information with an indication to a specific UE to respond with CAI-R, for example, one bit in the bitmap in the DCI can be mapped to a single UE. When set, the UE must send CAI-R. Alternatively, group common control information can be used with CAI-RNTI, and the UE configured with this RNTI responds with CAI-T. Alternatively, CAI-T can be sent in a UE-specific manner with a UE ID such as C-RNTI.

[0183] In an example scenario where UE3 has a bad channel and thus does not send CAI-R, the gNB does not transmit to UE3 in the directional COT. However, the gNB receives CAI-R1 and CAI-R2 from UE1 and UE2, respectively, indicating idle channels for UE1 and UE2. As a result, the gNB does not release the COT, but continues to communicate with UE1 and UE2 in the COT using appropriate beams. Fig. 9 Having shown an example embodiment, the individual steps are described below.

[0184] Step-1 TRP performs LBT using a spatial filter L.

[0185] Step-2 TRP sends CAI-T1 to UE1 and UE2 using filter D1.

[0186] Step-3 TRP sends CAI-T2 to UE3 using filter D2.

[0187] Step-4 UE senses the channel through CAT2 LBT. When the channel indicates a switch from DL to UL in a shared COT, sensing from multiple UEs can occur simultaneously.

[0188] Step-5, UE1 and UE2 send CAI-R1 and CAI-R2 respectively (it can be TDM or FDM or SDM or CDM), UE3 does not send CAI-R3. If CAI-R is in the form of PRACH resources, all UEs can send them on the same time-frequency resources.

[0189] In step-6, the gNB performs CAT2 sensing, and in step-7, the gNB sends COT information, reservation signal, control and data to UE1 and UE2.

[0190] In step-8 and step-9, UE1 senses the channel and sends it to gNB.

[0191] In step-8 and step-10, UE2 senses the channel and sends it to gNB.

[0192] Step-11, gNB releases the channel.

[0193] In an alternative embodiment, the gNB may resend CAI-T2 to UE3 again in the same COT to see if the channel is available to UE3. In another embodiment, UE1 sends CAI-R1 indicating an idle channel, and UE2 is interfered and does not send CAI-R2. In this case, the gNB determines that any transmission to UE1 may cause interference to the hidden node. Therefore, the gNB does not transmit on D1. Fig.10 An example embodiment with signaling is shown. The individual steps are described below.

[0194] Step-1 TRP performs LBT using a spatial filter L.

[0195] Step-2 TRP sends CAI-T1 to UE1 and UE2 using filter D1.

[0196] Step-3 TRP sends CAI-T2 to UE3 using filter D2.

[0197] Step-4 UE senses the channel through CAT2 LBT.

[0198] Step-5, UE1 and UE3 send CAI-R1 and CAI-R3. UE2 does not send CAI-R2.

[0199] Step-6 gNB senses the channel and at step-7, transmits to UE1 and UE3 on appropriate beams.

[0200] Step-8, DL-UL switching occurs in the shared COT of gNB; UE1 and UE3 sense the channel.

[0201] Step-9 and Step-10, which are sent to the gNB.

[0202] Step-11, gNB releases the channel.

[0203] In another embodiment, the gNB does not transmit to UE2 and determines the beam to transmit to UE1. Fig.11 Example signaling for this case is shown in FIG.

[0204] Step-1 TRP performs LBT using a spatial filter L.

[0205] Step-2 TRP sends CAI-T1 to UE1 and UE2 using filter D1.

[0206] Step-3 TRP sends CAI-T2 to UE3 using filter D2.

[0207] Step-4 UE senses the channel through CAT2 LBT.

[0208] Step-5, UE1 and UE3 send CAI-R1 and CAI-R3. UE2 does not send CAI-R2.

[0209] Step-6 gNB senses the channel and at step-7, transmits to UE3 on an appropriate beam.

[0210] In step-8, gNB does not send to UE1 and UE2.

[0211] Step-9 DL-UL switching occurs in the shared COT of the gNB; thereby UE3 senses the channel and in step-10 UE3 transmits to the gNB.

[0212] Step-11, gNB releases the channel.

[0213] CAI-T and CAI-R signaling

[0214] CAI-T can indicate the following information:

[0215] A. A spatial filter L that determines the spatial dimension of the directional COT;

[0216] B. Subbands on which the gNB has idle channels;

[0217] C. The subbands on which the UE must report the interference level in the CAI-R;

[0218] D. The spatial filter(s) that the UE must use to perform its LBT;

[0219] E. The identity of the sender;

[0220] F. The identity of the intended recipient; and

[0221] G. The possible duration of COT if the handshake is successful;

[0222] CAI-R can indicate the following information:

[0223] A. Interference level of one or more sub-bands within a directional COT;

[0224] B. Spatial filter Rm for LBT. This may be indicated as corresponding to the RS transmitted by the transmitter (gNB) or the QCL RS transmitted by the receiver (UE); and

[0225] C. COT of interference (if known by UE) - If the UE is able to detect the occupancy duration of the interfering node (such as the NAV of the WiGiG node), for example, through virtual sensing, the UE may indicate this information in the CAI-R.

[0226] The gNB may adjust its LBT subband or filter(s) based on the received CAI-R. Fig.12 In S1, the gNB receives CAI-R indicating that the UE's channel is idle in S1 and its interference is high in S2. Thus, the gNB only senses S1 and obtains COT in S1.

[0227] Based on the response from the receiver (UE in this case), the transmitter (gNB in ​​this case) can take one of the following actions:

[0228] A. If an RS for CAI-R such as DMRS is detected, but CAI-R is not detected, the gNB assumes that the UE receives CAI-T but there is no idle channel.

[0229] B. If the RS of CAI-R such as DMRS cannot be detected, the gNB assumes that the UE does not receive CAI-T or the UE does not have an idle channel.

[0230] C. If CAI-R is received and for one or more subbands an interference level above the threshold Sthresh dBm is indicated, the gNB shall release the channels in these subbands in the directional COT (in this case, the direction of the LBT filter L). Note that CAI-R can be sent after LBT with a less stringent energy detection threshold; and given the wideband channel and the large amount of available resources for CAI-R, CAI-R can still be received despite the presence of interference.

[0231] According to another embodiment, Fig.13A -B shows the gNB process for handling CAI-R. Fig.13A In the CAT4 LBT, if all subbands show interference, the gNB releases the directional COT and restarts a new CAT4 LBT. If a subset of subbands shows interference levels below the threshold, the gNB limits its COT to these subbands and transmits only in that subset of subbands.

[0232] According to Fig. 13B In an alternative embodiment of the example embodiment shown in , the gNB retransmits the CAI-T to the UE and waits for an acceptable CAI-R response. Since the channel is idle for the gNB, the gNB only uses CAT2 LBT before retransmitting.

[0233] If the number of CAI-T retransmissions in the COT exceeds the pre-configured number, the gNB can restart the LBT procedure using CAT4 LBT.

[0234] Fig.14A -B Diagram illustrates Fig.13A -B The timeline of the FBLBT process. Corresponds to Fig.13A , Fig.14A It shows the scenario where the gNB does not receive CAI-R in COT1. As a result, when the gNB accesses COT2, it attempts CAT4 based access to handshake with the UE in the next channel access attempt.

[0235] Alternatively, when the UE fails to send CAI-R, the gNB may not release the COT. It may send a signal to other UEs in COT1 or send a reservation signal. Fig. 13B , Fig. 14B It shows the scenario when the gNB obtains COT1 but does not receive CAI-R from the UE. Therefore, the gNB retransmits CAI-T in the same COT after a duration and finally receives CAI-R from the UE. During this duration, the gNB can maintain the COT by transmitting to other UEs or sending reservation signals.

[0236] In another example, if the COT duration of a UE’s interferer is known to the UE and the UE sends this information on the CAI-R, the gNB may resend the CAI-T to the UE when the COT of the interferer expires.

[0237] Improved channel sensing: short duration sensing for CAI-T and CAI-R

[0238] We now discuss an alternative embodiment of the sensing process described in Figure 6. Since CAI-T and CAI-R can be short duration signals that do not occupy much channel time, they can be sent after short duration sensing (such as fixed duration sensing like CAT2 LBT in sub-6 GHz). Fig.15 An example timeline of gNB and UE functionality is shown in . If the CAI-R indicates an idle channel, the gNB can perform random backoff based channel sensing such as CAT4 LBT to send COT information, control and data. This scheme allows the gNB to quickly check whether the UE's environment is idle in the desired spatial direction before accessing the channel for data transmission. However, the delay in random backoff LBT can make the UE's feedback on CAI-R outdated. Therefore, the LBT process can be constrained with a maximum time, after which the gNB channel access fails and the CAI-T must be resent again to initiate a channel access attempt.

[0239] Optional transmission of CAI-T and CAI-R

[0240] According to another embodiment as shown in FIG. 6 , the network may determine whether FBLBT is required. When CAI-T and CAI-R are not sent during the channel access process, that is, when handshaking is not performed, such as Fig.16A - As shown in the embodiment shown in FIG. 8B , channel access is considered as non-feedback based LBT (NFBLBT). Fig.16A Overlapping LBT beams and transmit beams are shown. Fig. 16B The spatial filters used in LBT and the signaling between gNB and UE are shown. The main steps of the process are described below.

[0241] 1. The gNB selects a spatial filter L for LBT from a set of possible LBT spatial filters {F} and performs channel sensing.

[0242] 2. When there is an idle channel, the gNB transmits one or more of COT information, control information, data, channel reservation (CR) signaling by using one or more spatial filters from a set of spatial filters {D} that meet the requirements for operating on a channel obtained by the LBT filter L. In this example, the gNB transmits on two beams Dk, Dl∈{D}.

[0243] 3. The UE senses the channel using a short duration sensing procedure like CAT2 LBT using a spatial filter Rp∈{R}. The set of filters {R} is determined according to L. The gNB provides an implicit or explicit indication to the UE to determine Rp. For example, if the gNB provides an UL grant to the UE, Rp can be the filter used to send PUSCH DMRS. Alternatively, Rp can be selected based on the TCI state of the DMRS of the CORESET that provides the grant. As another alternative, the COT indication or CR signal or a combination of COT information and CR can directly indicate Rp, or indicate L from which the UE can infer Rp.

[0244] 4. Upon finding that the channel is idle, the UE sends data and / or control information using the spatial filter Rq.

[0245] 5. Once the communication is completed, the gNB releases the channel by stopping transmission on the channel.

[0246] Fig.17 The example embodiment in FIG. 4 shows the time axis of the channel sensing and transmission from the gNB and the COT obtained by the UE at the gNB.

[0247] Flexible application of FBLBT and NFBLBT processes

[0248] FBLBT may not be required in every deployment. Given that the beams are highly directional, in many cases the receiver is able to effectively suppress interference from hidden nodes. However, in dense networks and high traffic scenarios, FBLBT may be a better choice to improve spatial reuse while managing interference from hidden nodes.

[0249] FBLBT can be used when the LBT spatial filter L meets certain conditions. This can include, for example, if the HPBW of the beam from L is less than a certain threshold θHPBW,thresh. This ensures that the overhead associated with CAI-T and CAI-R signaling is reduced when the network can tolerate LBT over a wide spatial angle, such as when using omni-directional and quasi-omni-directional filters. θHPBW,thresh can be configured by the network.

[0250] Alternatively, the spatial filter may be associated with a scheme of transmitting CAI-T / CAI-R or not transmitting CAI-T / CAI-R. For example, a DL spatial filter quasi-co-located with a certain DL RS or a UL spatial filter corresponding to a DL RS may be configured to transmit or not transmit CAI.

[0251] The type of LBT (FBLBT or NFBLBT) can be configured by the network. In one example, this information can be provided through broadcast system information (SI) such as RMSI or OSI. Thus, all devices in the network use one form of LBT. In another example, the network can determine an increase in interference to the receiver or transmitter deafness in certain spatial locations, so that FBLBT can be activated only for devices determined to be located in these locations, while other devices can use NFBLBT. Here, transmissions that are quasi-co-located with a subset of RSs use FBLBT. This configuration can be provided in a UE-specific manner or in a multicast manner through upper layer signaling. Therefore, transmissions that are quasi-co-located or corresponding (in the reverse link) with certain SSBs or CSI-RS or SRS can use FBLBT. A UE can be connected to two TRPs in the same cell and use NFBLBT on the link with TRP1 and FBLBT on the link with TRP2, such as Fig.18 as shown in .

[0252] In another example, the type of LBT can be determined dynamically. If the node receives CAI-T, it infers that the FBLBT process is required, so it sends CAI-R. If the node does not receive CAI-T, but directly receives a control or data signal, it infers that the NFBLBT process is required, so it does not send CAI-R.

[0253] The type of LBT can be determined based on certain CSI-RS measurements. If the measured power level is below a certain threshold, FBLBT may be preferred. Similarly, the type of LBT can be determined based on the interference level observed through energy detection. If the interference level exceeds a certain threshold, FBLBT may be preferred.

[0254] In addition, the spatial filter Rp used for sensing before the UE's transmission in the COT acquired by the gNB can be configured differently for the FBLBT and NFBLBT methods. For example, for FBLBT, the network can tolerate more directional LBT without negative impact because the handshake ensures a clear channel at both the transmitter and the receiver. On the other hand, for NFBLBT, a wider filter may be required.

[0255] If the FBLBT-based channel access is successful and the first COT is obtained, the communication node may not perform FBLBT for a duration T after obtaining the first COT. This helps save the minimal overhead caused by the handshake process. For example, the gNB may obtain the first COT through FBLBT and provide the UE with a UL grant outside the first COT. The UE may not need to perform FBLBT to obtain the COT for UL transmission. Instead, the UE may perform NFBLBT and send PUSCH.

[0256] Adaptive LBT

[0257] In the CAT4 LBT process in sub-6GHz frequencies, if the channel is available within the initial CCA period (using short duration sensing), the node performs an extended CCA (eCCA) by setting a counter with a random backoff value within the duration of its contention window. The node defers transmission until the counter reaches 0. During this period, the node periodically senses the channel for the duration of one eCCA slot. If it senses a busy channel, it pauses the counter. Otherwise, it decrements the counter. When the counter reaches zero, the node starts transmitting.

[0258] This process may be suitable for managing spectral reuse in a network by adjusting the spatial filters during the LBT process. A node may begin idle mode sensing using spatial filter L1. If the node does not obtain an idle channel, it may restart sensing using a narrower beam L2, and if that fails, it may sense using another beam using spatial filter L3 with a different orientation, or using an even narrower beam L4. The node may continue in this manner until it finds a spatial filter with the smallest allowed angular spread for which the channel is idle. Fig.19 The beams generated using spatial filters L1, L2, L3 and L4 are illustrated in the example embodiment of FIG. Fig. 20 An example timeline of sensing during an initial period in which the LBT spatial filter is adjusted is shown.

[0259] If the node obtains an idle channel in the initial sensing phase using filter L1, the node starts the extended sensing phase using L1. However, if the node senses a busy channel using L1 within the duration given by the timer busy counter, the node can select L2 to continue sensing during the extended period. The busy counter is set each time the spatial filter used for sensing is updated (based on the configuration provided by the upper layer), and the busy counter is counted down when the postponement period counter is suspended. Fig.21 The time axis is represented in FIG, where the UE starts with the LBT spatial filter L1. During the hold-off period, it senses a busy channel for a duration exceeding the busy counter. Thus, the UE continues channel sensing using L2 which has a narrower beam and allows idle channels. When the hold-off period is successfully completed, the UE gains channel access using the COT in the spatial direction given by L2.

[0260] In some use cases, it may be beneficial to configure the busy counter per beamwidth or angular spread or HPBW. For example, the wider the beam, the shorter the busy counter. This enables fast adaptation to narrow spatial channels.

[0261] In such Fig. 22 In another example embodiment shown in , a UE for channel access using LBT beam adaptation is shown. Here, the UE starts an initial CCA using spatial filter L1. During the eCCA period, if the busy counter counts down to 0, the UE changes the beam and continues sensing.

[0262] Contention Window Size (CWS) Adjustment in FBLBT

[0263] Acknowledgements in response to transmissions such as PDSCH or PUSCH are used to set the size of the contention window. If a negative acknowledgement is encountered, the window size is increased to allow more time for channel access, within which the interference is expected to terminate and the channel will be idle. It is contemplated that CAI-R may also be used to adjust the CWS for FBLBT. A transmitter may increase its CWS under the following conditions:

[0264] A. The transmitter did not receive the CAI-R. This can happen if the receiver did not receive the CAI-T and therefore did not send the CAI-R. Or it can happen if the transmitter's channel is bad and therefore it cannot detect the CAI-R.

[0265] B. CAI-R is received, but CAI-R indicates interference exceeding the threshold Sthresh dBm.

[0266] Otherwise, if CAI-R is received and the interference is below Sthresh dBm, the CWS may be kept unchanged. Otherwise, the CWS is adjusted based on the interference level; generally, the CWS is increased in response to the increased interference level. In this case, the HARQ confirmation bits (for CBG or TB) may further affect the CWS. Even if the receiver's channel is poor, the receiver may be able to send CAI-R because CAI-R is expected to have a short duration and wide bandwidth. However, the channel conditions may not be good enough to support data transmission.

[0267] When using energy detection based sensing, a node may use a higher threshold for the LBT process before CAI-R transmission. However, a node may use a lower threshold for LBT before data transmission. Thus, CAI-R may be sent taking into account interference. CAI-T may indicate a threshold for channel access for CAI-R.

[0268] In an alternative embodiment of this aspect, if CAI-R is received and the interference is below Sthresh dBm, the CWS is reset to the minimum value. In addition, HARQ acknowledgement bits (to CBG or TB) may affect the CWS. Fig.23 Adjusting the CWS is shown in the exemplary embodiment illustrated in FIG.

[0269] Acquisition of COT in multiple spatial directions and in multiple sub-bands

[0270] According to another aspect of the present application, a node may acquire (one or more) COTs in more than one spatial direction. In addition, since there may be one or more subbands available, each directional COT corresponds to a certain set of subbands of the access channel. Fig.24A Here, two sub-bands are available in the spectrum and the TRP obtains channel access in two directions - directional COT using L1 in sub-bands S1 and S2 and directional COT using L2 in sub-band S1.

[0271] These COTs may start at different times but partially overlap in time, e.g. Fig. 24B In another alternative embodiment, the directional COTs can start at the same time and can end at the same or different times, such as Fig.24C Typically, a node must mute its transmission on L1 to sense L2 to avoid self-interference. If one direction falls within the null of the other direction, then the mute may not be needed. Multiple TRPs for a single cell can be obtained as follows: Fig. 24B Channel access shown in .

[0272] for Fig.24C The operation in the channel can obtain channel access in the following manner. In one method, the node selects the spatial direction L1 on which it will perform LBT with random backoff, such as CAT4 LBT, in the broadband that is the aggregation of subbands S1 and S2. It senses other spatial directions such as L2 on subband S1 using short duration LBT, such as CAT2 LBT. Fig.25A As shown. Certain restrictions may be introduced for the spatial directions used for CAT2 LBT. The restrictions may include, for example, that the angular spread of L2 is less than or equal to the angular spread of L1. By performing CAT4 on narrow beams and CAT2 LBT on wider beams, greedy channel access is avoided. There may also be restrictions on the number of beams or the total angular spread of access channels via CAT2 LBT. In addition, CAT2 LBT may not be used to access channels on the spectrum outside of the sub-bands obtained via CAT4 LBT - for example, sub-band S3 cannot be accessed via CAT2 LBT using filter L2.

[0273] In another approach, a node performs LBT with random backoff using multiple directional filters. A node can transmit in the direction in which its LBT succeeds, with possible self-delay to align all directional COTs. This is exemplified in Fig.25B middle.

[0274] like Fig.26 Another example embodiment shown in describes FBLBT. For CAI-T transmission, sensing is performed on subband S1 using spatial filter L. However, after receiving CAI-R from the UE, the gNB can also perform CAT2 sensing on S2 using spatial filter L (in addition to sensing in S1). If S2 is also idle, the gNB acquires the channels in S2 and aggregates the subbands in this directional COT.

[0275] Directional COT information indication

[0276] When the gNB confirms that it has reserved the channel, COT related information can be explicitly signaled. The gNB can indicate the COT in a broadcast or multicast manner so that other nodes can read the signal and avoid unsuccessful channel attempts when the channel is occupied. The signal can be in the form of a channel reservation signal or a control signal, or a combination of both. It can be a preamble that can be read by other networks such as WiGiG. Alternatively, the COT related information can be read by at least a node within the network or a node outside the network, but using the same technology as the transmitter. Alternatively, the COT related information can be unicast to the UE communicating with the gNB during this channel access.

[0277] Alternatively, the gNB may indicate the COT information in the CAI-T. If no CAI-R is received or a subsequent short duration CCA fails, the gNB releases the COT early. This may cause other nodes to back off channel access based on the CAI-T for a period longer than the actual channel occupancy time, but may reduce the overhead from separate COT information signaling.

[0278] The COT indicator may provide one or more of the following types of information. These aspects may be described in conjunction with FIG. 6 and FIG. 16:

[0279] A. Transmitter ID, which can be a network ID such as cell ID or TRP-ID, or a UE ID such as C-RNTF.

[0280] B. Receiver ID, which can be a network ID such as cell ID or TRP-ID, or a UE ID such as C-RNTI, or a multicast identifier such as COT-RNTI, or a broadcast identifier such as B-COT-RNTI.

[0281] C. The duration that the channel will be occupied starting from a reference time. The reference time may correspond to the start or end of an OS or mini-slot or timeslot or sub-frame or frame carrying a COT indicator. The duration of channel occupancy may be indicated by the number of OS or mini-slots or timeslots or sub-frames and may be provided as an index into a pre-configured table of possible values.

[0282] D. Spatial filter information about L (LBT filter). This can be provided as an index into a table of possible values ​​for the spatial filter. For example, the spatial filter L is indicated as being in a quasi-co-located state with one of the SSB or CSI-RS. Upon receiving this, the receiver identifies the spatial dimensions of the transmitter's COT. The UE can use this information to select the LBT spatial filter Rm for channel sensing before sending the CAI-R.

[0283] E. Spatial filter information about Di (LBT filter). This can also be provided as an index into a table of possible values ​​for the spatial filter and can be defined by a quasi-co-location relationship with the RS known to the UE. The UE can use this information to select the LBT spatial filter Rp for channel sensing before sending control or data.

[0284] F. Resources used to send CAI-R. The time and frequency resources used for CAI-R can be explicitly indicated in CAI-T. This can be in the form of PDSCH grant or PUCCH resources CAI-R or RACH resources for CAI-R.

[0285] G. Explicit indication of spatial filter Rm or Rp (filter for receiver LBT) An explicit RS may be indicated to the UE as a beam for channel sensing prior to transmission of CAI-R.

[0286] H. The bandwidth within which the UE must perform LBT and report via CAI-R. After performing LBT on a certain bandwidth BL using a spatial filter L, the gNB may send CAI-R on BL. However, DL data transmission may want to be performed on bandwidth BD. Thus, the UE is required to perform LBT on BD. Therefore, the gNB indicates BD as the bandwidth for the UE to perform LBT.

[0287] I. Channel sensing threshold Vthresh, which is used to determine whether the channel is idle. If the sensed energy exceeds Vthresh, the node considers the channel busy. For FBLBT, Vthresh can be determined based on feedback from CAI-R. Vthresh may be different for different subbands and spatial directions. Therefore, it can be provided per subband and directional COT.

[0288] Virtual sensing using channel reservation signal or COT indication

[0289] When a node, such as Fig.27A In the example embodiment in FIG. 1 , TRP1, while listening to check if the channel is idle, may obtain COT information about the transmission from TRP2. This can be done, for example, by detecting a channel reservation (CR) signal. The reservation signal itself indicates the COT information, or the presence of the reservation signal means that the COT information follows the control signal. Upon detecting the COT information, TRP1 identifies the time, subband, and spatial resource information of the transmission of TRP2. While the time and subband information can be understood directly, the spatial information is interpreted using the spatial filter used to detect the reservation signal. If the spatial filter L1 is used to determine the directional COT, TRP1 does not need to use L1 to sense the channel at least until the time of the COT expires in the indicated subband. This may also mean that TRP1 does not need to sense the channel using certain spatial filters that may partially or completely overlap with L1 during the COT and in the indicated subband.

[0290] exist Fig.27BIn the example, TRP1 uses spatial filter L1 to detect channel occupancy in S1 and S2 for a duration indicated in TRP2's COT indicator. Thus, TRP1 does not access channels in S1 and S2 using filter L1 until TRP2's COT expires. In fact, TRP1 may sleep for this duration, saving power. This is a form of virtual sensing. In other words, the COT information received using filter L1 is used to indicate a duration for which sensing is meaningless because another node is using the channel.

[0291] This does not prevent TRP1 from using filter L1 to access channels in subbands that are not included in the COT of TRP2. Fig.28A Network configuration and Fig.28B Here, TRP1 detects the COT information of TRP2 and subbands S1 and S2 using spatial filter L1. During the duration of TRP2's COT, TRP1 does not access S1 and S2 using L1. Instead, TRP1 accesses the channel in S2 using spatial filter L1. Since the COTs of TRP1 and TRP2 are separated in frequency, there is no mutual interference.

[0292] TRP1 can also access the channel on a non-overlapping spatial filter L2 that overlaps with the COT of TRP2, as in Fig.29A Network configuration and Fig.29B When TRP2 is detected to be occupying S1 and S2 by using filter L1, TRP1 selects the spatial direction L2 which does not overlap with spatial filter L1 and performs channel access, thereby obtaining directional COTs of S1 and S2.

[0293] According to another embodiment, a process for selecting a spatial domain filter when one or more CR signals and COT information are received from other nodes is described. Node X (which can be a UE or a TRP) monitors COT indications from other nodes. When node X detects a COT indicator using spatial filter L1, it stores the indicated duration, subband, and its own spatial filter L1. If node X receives multiple COT indicators, it can maintain a table of such values. An example is shown in Table 2 below.

[0294]

[0295] Table 2

[0296] To access the channel, node X ensures that it selects a channel resource that does not interfere with the entries in the table in time, frequency, or space. Once the COT expires for an entry in the table, node X can delete the entry from the table. When node X receives a single COT indicator from node Y and determines its channel access resource based on the COT indicator, the process is shown in Fig.30 In the example embodiment of . Node X determines a set of filters {L1'} that may overlap with L1 and cannot be used in the set of subbands {S} indicated by the COT indicator during the duration of node Y's COT. If node X must access the channel at the same time as node Y's COT, node X cannot use the channel resources corresponding to {L1'} and {S}. Outside the duration of node Y's COT, node X has no restrictions on accessing the channel.

[0297] Although the systems and methods are described in terms of what are presently considered to be specific aspects, the present application need not be limited to the disclosed aspects. It is intended to cover various modifications and similar arrangements contained within the spirit and scope of the claims, and the scope of the claims should be given the broadest interpretation so as to include all such modifications and similar structures. The present disclosure includes any and all aspects of the following claims.

Claims

1. A method for obtaining channel access in a network, comprising: Selecting, via the gNodeB (gNB), a spatial filter from a first set of spatial filters for listen before talk (LBT); Detect idle channels via gNB; obtaining a directional channel occupancy time (COT) in the channel in the direction of the selected spatial filter; sending a channel access indicator transmission (CAI-T) to the node on the beam within the COT via a spatial filter in the second set of spatial filters, wherein the CAI-T includes an indication of the selected spatial filter and an indication of a duration of the directional COT; receiving a channel access indicator response (CAI-R) from a node, wherein the CAI-R includes an indication of interference levels for one or more subbands within the directional COT; sensing via the short channel and sensing via the spatial filter or another spatial filter in the second set of spatial filters that the channel is idle; and Information is sent to the node via the channel using one or more spatial filters from a second set of spatial filters.

2. The method according to claim 1, further comprising: terminating transmission on the channel; and The channel is released based on one or more of the presence, absence, and content of the CAI-R.

3. The method according to claim 1, wherein The beam comprises a plurality of beams, The node includes a plurality of nodes, and Each beam of the plurality of beams supports one or more nodes of the plurality of nodes.

4. The method according to claim 3, wherein The CAI-R is not received from a node in the plurality of nodes, and The transmission is either not transmitted to the one of the plurality of nodes, or not transmitted to the one of the plurality of nodes and another node of the plurality of nodes that share one beam of the plurality of beams.

5. The method according to claim 1, further comprising: A CAI-T is retransmitted to the node or a CAI-R is received from the node.

6. The method of claim 1, wherein the contention size window (CSW) is adjusted taking into account feedback indicated by the CAI-R.

7. The method of claim 1, wherein detecting the channel is performed across multiple beams in different sub-bands.

8. The method of claim 1, wherein the information comprises one or more of COT information, channel access duration, control information, data, subband indication, spatial filter information, and channel reservation signaling.

9. The method of claim 1, wherein the node is a user equipment.

10. A device comprising: Non-transitory memory for obtaining channel access in a network; and A processor operably coupled to the non-transitory memory, the processor configured to execute the following instructions: receiving a Channel Access Indicator Transmission (CAI-T) from a gNodeB (gNB) on a beam within a channel occupation time (COT) of the channel; selecting a spatial filter from a set of spatial filters based on the CAI-T, wherein the CAI-T includes an indication of the selected spatial filter and an indication of a duration of the COT; sensing via the short channel and sensing via a selected spatial filter of the set of spatial filters; sending a channel access indicator response (CAI-R) to a gNodeB using the selected spatial filter or another spatial filter from the set of spatial filters, wherein the CAI-R includes an indication of interference levels for one or more subbands within the COT; Receive information from gNodeB; sensing via short channel sensing and a second spatial filter in the set of spatial filters; Make sure the channel is idle; and One or more of data and control information are sent to the gNB via a third filter in the set of spatial filters.

11. The device according to claim 10, wherein the device is configured to access the channel simultaneously in multiple spatial directions.

12. The apparatus of claim 11, wherein accessing the channel via one of the spatial directions is based on backoff, and accessing the channel via another of the spatial directions is based on short channel sensing.

13. The apparatus of claim 10, wherein the beam comprises a plurality of beams supporting the apparatus and the one or more nodes, and each of the plurality of beams supports at least one of the apparatus and the one or more nodes.

14. The apparatus of claim 13, wherein The CAI-R is not transmitted by one of the nodes or the device on one of the plurality of beams, and The control information from the gNodeB is either not transmitted to the one of the multiple nodes or the device, or is not transmitted to the one of the multiple nodes and the device sharing one of the multiple beams.

15. The apparatus of claim 10, further comprising: Receive retransmission of CAI-T.

16. The apparatus of claim 10, wherein a contention size window (CSW) is adjusted taking into account feedback indicated by the CAI-R.

17. A device comprising: Non-transitory memory for obtaining channel access in a network; and A processor operably coupled to the non-transitory memory, the processor configured to execute the following instructions: Selecting a spatial filter from a first set of spatial filters to perform listen-before-talk (LBT); obtaining a directional channel occupancy time (COT) in the channel in the direction of the selected spatial filter; sending a channel access indicator transmission (CAI-T) to the node on the beam within the COT via a spatial filter in the second set of spatial filters, wherein the CAI-T includes an indication of the selected spatial filter and an indication of a duration of the directional COT; receiving, via the node, a channel access indicator response (CAI-R), wherein the CAI-R includes an indication of interference levels for one or more subbands within the directional COT; sensing via a short channel and using the spatial filter or another spatial filter in a second set of spatial filters to sense that the channel is idle; and Information is sent to the node via the channel using one or more spatial filters from a second set of spatial filters.

18. The apparatus of claim 17, further comprising: terminating transmission on the channel; and The channel is released based on one or more of the presence, absence, and content of the CAI-R.

19. The apparatus of claim 17, wherein The beam comprises a plurality of beams, The node includes a plurality of nodes, Each of the plurality of beams supports one or more of the plurality of nodes, the CAI-R is not received from one of the plurality of nodes, and The transmission is either not transmitted to the one of the plurality of nodes, or not transmitted to the one of the plurality of nodes and another node of the plurality of nodes that share one beam of the plurality of beams.

20. The apparatus of claim 17, further comprising: Resend CAI-T to the node.

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