WO2020117593A9 - Ul licensed band and dl unlicensed band mechanisms - Google Patents

Abstract

Segregated use of the licensed and unlicensed band is described herein. The licensed band is limited to uplink transmissions. Uplink transmissions, including PRACH transmissions, are limited to the licensed band or based on control signaling from a gNB as to whether to be transmitted on the unlicensed band. Whether uplink transmissions are to be provided on the licensed band is based on the SSB-RSRP meeting an indicated threshold or a licensed band/unlicensed band indicator in a DCI. The UE ignores the SSB-RSRP if the indicator is present.

Description

UL LICENSED BAND AND DL UNLICENSED BAND MECHANISMS

[0001] This application claims the benefit of priority to U.S. Provisional

Patent Application Serial No. 62/774,501, filed December 3, 2018, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] Embodiments pertain to radio access networks (RANs). Some embodiments relate to cellular networks, including Third Generation Partnership Project (3GPP) Long Term Evolution (LTE), 4^th generation (4G) and 5^th generation (5G) New Radio (NR) (or next generation (NG)) networks. Some embodiments relate to unlicensed band use in such networks.

BACKGROUND

[0003] The use of various types of systems has increased due to both an increase in the number and types of user equipment (UEs) using network resources as well as the amount of data and bandwidth being used by various applications, such as video streaming, operating on these UEs. Bandwidth, latency, and data rate enhancement may be used to deliver the continuously- increasing demand for network resources. The next generation wireless communication system will provide ubiquitous connectivity and access to information, as well as ability to share data, by various users and applications. NG systems are expected to have a unified framework in which different and sometimes conflicting performance criteria and services are to be met. In general, NR will evolve based on 3 GPP LTE- Advanced technology with additional enhanced radio access technologies (RATs) to enable seamless wireless connectivity solutions. An increasing number of these solutions involve the issue of the massive increase in number of UEs in use. In particular, a number of developments have focused on the use of the unlicensed spectrum to provide additional communication channels with which the base stations and UEs communicate.

BRIEF DESCRIPTION OF THE FIGURES

[0004] In the figures, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The figures illustrate generally, by way of example, but not by way of limitation, various aspects discussed in the present document.

[0005] FIG. 1 illustrates combined communication system in accordance with some embodiments.

[0006] FIG. 2 illustrates a block diagram of a communication device in accordance with some embodiments.

[0007] FIG. 3 illustrates NR deployment scenarios in accordance with some embodiments.

[0008] FIG. 4 illustrates an NR cell using unlicensed band downlink transmissions and licensed band uplink transmissions in accordance with some embodiments.

[0009] FIG. 5 illustrates a method of communication of a UE in accordance with some embodiments.

[0010] FIG. 6 illustrates a method of communication of a base station in accordance with some embodiments

DETAILED DESCRIPTION

[0011] The following description and the drawings sufficiently illustrate specific aspects to enable those skilled in the art to practice them. Other aspects may incorporate structural, logical, electrical, process, and other changes.

Portions and features of some aspects may be included in, or substituted for, those of other aspects. Aspects set forth in the claims encompass all available equivalents of those claims.

[0012] FIG. 1 illustrates a combined communication system in accordance with some embodiments. The system 100 includes 3GPP LTE/4G and NG network functions. A network function can be implemented as a discrete network element on a dedicated hardware, as a software instance running on dedicated hardware, or as a virtualized function instantiated on an appropriate platform, e.g., dedicated hardware or a cloud infrastructure.

[0013] The evolved packet core (EPC) of the LTE/4G network contains protocol and reference points defined for each entity. These core network (CN) entities may include a mobility management entity (MME) 122, serving gateway (S-GW) 124, and paging gateway (P-GW) 126.

[0014] In the NG network, the control plane and the user plane may be separated, which may permit independent scaling and distribution of the resources of each plane. The UE 102 may be connected to either an access network or radio access network (RAN) 110 and/or may be connected to the NG-RAN 130 (gNB) or an Access and Mobility Function (AMF) 142. The RAN 110 may be an eNB or a general non-3GPP access point, such as that for Wi-Fi. The NG core network may contain multiple network functions besides the AMF 112. The UE 102 may generate, encode and perhaps encrypt uplink transmissions to, and decode (and decrypt) downlink transmissions from, the RAN 110 and/or gNB 130 (with the reverse being true by the RAN 110/gNB 130).

[0015] The network functions may include a User Plane Function (UPF)

146, a Session Management Function (SMF) 144, a Policy Control Function (PCF) 132, an Application Function (AF) 148, an Authentication Server Function (AUSF) 152 and User Data Management (UDM) 128. The various elements are connected by the NG reference points shown in FIG. 1.

[0016] The AMF 142 may provide UE-based authentication, authorization, mobility management, etc. The AMF 142 may be independent of the RATs used. The SMF 144 may be responsible for session management and allocation of IP addresses to the UE 102. The SMF 144 may also select and control the UPF 146 for data transfer. The SMF 144 may be associated with a single session of the UE 102 or multiple sessions of the UE 102. This is to say that the UE 102 may have multiple 5G sessions. Different SMFs may be allocated to each session. The use of different SMFs may permit each session to be individually managed. As a consequence, the functionalities of each session may be independent of each other. The UPF 126 may be connected with a data network, with which the UE 102 may communicate, the UE 102 transmitting uplink data to or receiving downlink data from the data network.

[0017] The AF 148 may provide information on the packet flow to the

PCF 132 responsible for policy control to support a desired QoS. The PCF 132 may set mobility and session management policies for the EE 102. To this end, the PCF 132 may use the packet flow information to determine the appropriate policies for proper operation of the AMF 142 and SMF 144. The AUSF 152 may store data for EE authentication. The EE)M 128 may similarly store the EE subscription data.

[0018] The gNB 130 may be a standalone gNB or a non- standalone gNB, e.g., operating in Dual Connectivity (DC) mode as a booster controlled by the eNB 110 through an X2 or Xn interface. At least some of functionality of the EPC and the NG CN may be shared (alternatively, separate components may be used for each of the combined component shown). The eNB 110 may be connected with an MME 122 of the EPC through an SI interface and with a SGW 124 of the EPC 120 through an Sl-U interface. The MME 122 may be connected with an HSS 128 through an S6a interface while the TE)M is connected to the AMF 142 through the N8 interface. The SGW 124 may connected with the PGW 126 through an S5 interface (control plane PGW-C through S5-C and user plane PGW-U through S5-U). The PGW 126 may serve as an IP anchor for data through the internet.

[0019] The NG CN, as above, may contain an AMF 142, SMF 144 and

UPF 146, among others. The eNB 110 and gNB 130 may communicate data with the SGW 124 of the EPC 120 and the UPF 146 of the NG CN. The MME 122 and the AMF 142 may be connected via the N26 interface to provide control information there between, if the N26 interface is supported by the EPC 120. In some embodiments, when the gNB 130 is a standalone gNB, the 5G CN and the EPC 120 may be connected via the N26 interface.

[0020] FIG. 2 illustrates a block diagram of a communication device in accordance with some embodiments. In some embodiments, the communication device may be a UE (including an IoT device and NB-IoT device), eNB, gNB or other equipment used in the 4G/LTE or NG network environment. For example, the communication device 200 may be a specialized computer, a personal or laptop computer (PC), a tablet PC, a mobile telephone, a smart phone, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. In some embodiments, the communication device 200 may be embedded within other, non-communication-based devices such as vehicles and appliances.

[0021] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules and components are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a machine readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations.

[0022] Accordingly, the term“module” (and“component”) is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be

instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software, the general-purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

[0023] The communication device 200 may include a hardware processor 202 (e.g., a central processing unit (CPU), a GPU, a hardware processor core, or any combination thereof), a main memory 204 and a static memory 206, some or all of which may communicate with each other via an interlink (e.g., bus) 208. The main memory 204 may contain any or all of removable storage and non-removable storage, volatile memory or non-volatile memory. The communication device 200 may further include a display unit 210 such as a video display, an alphanumeric input device 212 (e.g., a keyboard), and a user interface (UI) navigation device 214 (e.g., a mouse). In an example, the display unit 210, input device 212 and UI navigation device 214 may be a touch screen display. The communication device 200 may additionally include a storage device (e.g., drive unit) 216, a signal generation device 218 (e.g., a speaker), a network interface device 220, and one or more sensors, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The communication device 200 may further include an output controller, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

[0024] The storage device 216 may include a non-transitory machine readable medium 222 (hereinafter simply referred to as machine readable medium) on which is stored one or more sets of data structures or instructions 224 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 224 may also reside, successfully or at least partially, within the main memory 204, within static memory 206, and/or within the hardware processor 202 during execution thereof by the communication device 200. While the machine readable medium 222 is illustrated as a single medium, the term "machine readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 224.

[0025] The term“machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the communication device 200 and that cause the communication device 200 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine-readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine-readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks.

[0026] The instructions 224 may further be transmitted or received over a communications network using a transmission medium 226 via the network interface device 220 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks. Communications over the networks may include one or more different protocols, such as Institute of Electrical and Electronics

Engineers (IEEE) 802.11 family of standards known as Wi-Fi, IEEE 802.16 family of standards known as WiMax, IEEE 802.15.4 family of standards, a Long Term Evolution (LTE) family of standards, a Universal Mobile

Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, a NG/NR standards among others. In an example, the network interface device 220 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the transmission medium 226.

[0027] The communication device 200 may be an IoT device (also referred to as a“Machine-Type Communication device” or“MTC device”), a narrowband IoT (NB-IoT) device, or a non-IoT device (e.g., smart phone, vehicular UE), any which may communicate with the core network via the eNB or gNB shown in FIG. 1. The communication device 200 may be an

autonomous or semiautonomous device that performs one or more functions, such as sensing or control, among others, in communication with other communication devices and a wider network, such as the Internet. If the communication device 200 is IoT device, in some embodiments, the

communication device 200 may be limited in memory, size, or functionality, allowing larger numbers to be deployed for a similar cost to smaller numbers of larger devices. The communication device 200 may, in some embodiments, be a virtual device, such as an application on a smart phone or other computing device.

[0028] As above, UEs typically operate in the licensed spectrum.

However, the increasing scarcity of licensed spectrum in LTE and NR frequency bands due to the explosion of UEs may result in insufficient bandwidth to supply all UEs in a network for communication. This may lead to, among other things, a reduction in data throughput and a reduction in communication quality. To ameliorate this issue, NR (and LTE) systems may operate in the unlicensed spectrum (called NR-unlicensed or NR-U). Potential NR operation in unlicensed spectrum includes, but is not limited to, Carrier Aggregation (CA) based on Licensed Assisted Access (LAA)/enhanced LAA (eLAA) systems, NR operation in the unlicensed spectrum via dual connectivity (DC), and standalone NR (in which the NR networks may or may not be supported by a 4G structure) and LTE systems in the unlicensed spectrum.

[0029] When using the unlicensed bands, communication devices such as base stations (gNBs) and UEs may determine channel availability via energy detection before transmitting data on the channel. For example, the

communication device may determine that the channel is occupied through a predetermined amount of energy being present in the channel or via a change in a received signal strength indication (RSSI). The unlicensed channel may be reserved using a reservation signal to prevent WiFi signals from initiating transmission until the next frame boundary event. Thus, communication devices may contend for access to the unlicensed frequency band by performing clear channel assessment (CCA) and Listen-Before-Talk (LBT) procedures, and subsequently transmitting during transmission opportunities (TxOPs).

[0030] The LBT-based channel access mechanism may thus

fundamentally resemble the WLAN’s Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) principles. Any node that intends to transmit in unlicensed spectrum may first perform a channel sensing operation (of, say 25ms) before initiating any transmission. An additional random back-off mechanism may be adopted (in category 4 LBT) to avoid collisions when more than one node senses the channel as idle (using, e.g., average energy detection within the channel) and transmits simultaneously.

[0031] FIG. 3 illustrates deployment scenarios in accordance with some embodiments. Specifically, FIG. 3 illustrates different deployment scenarios into which NR-U technologies can be categorized. In each scenario, the transmitter may encode signals for delivery to the receiver, and the receiver may decode the signals from the transmitter. As shown, scenario 1 shows carrier aggregation (CA) between licensed band NR (primary cell (PCell)) and NR-U (secondary cell (SCell)). In this scenario, the NR-U SCell may communicate with the UE using both DL and UL, or may provide DL-only transmissions. CA may permit the UE to simultaneously transmit and receive data on multiple component carriers from a single eNB/gNB.

[0032] Scenario 2 shows dual connectivity (DC) between a licensed band

LTE (PCell) and NR-U (primary secondary cell (PSCell)). DC may permit the UE to simultaneously transmit and receive data on multiple component carriers from two cell groups via master eNB (MeNB/gNB) and secondary eNB

(SeNB/gNB).

[0033] Scenario 3 shows a stand-alone NR-U. In the stand-alone NR-U, the UE may access a standalone NR carrier and may not be connected to an LTE carrier. Scenario 4 shows an NR cell in which the unlicensed band is used for DL transmissions and the licensed band is used for UL transmissions. Scenario 5 shows DC between licensed band NR (PCell) and NR-U (PSCell).

[0034] Scenario 4, which uses the unlicensed band for DL transmissions and the licensed band for UL transmissions, is different from other deployment scenarios in which the unlicensed band may be used for either or both the DL and UL transmissions. In this scenario, each cell contains at least one licensed band(s) and at least one unlicensed band(s), where the licensed band supports UL transmission and the unlicensed band supports DL transmission inside the cell. As both licensed band and unlicensed band may be present in the same cell, additional operations may be used to support UL and DL transmissions and receptions. Note that in scenario 4, as in the other scenarios, the eNB and gNB may be logically separate, as shown, but physically co-located.

[0035] In some embodiments, the system may use licensed band operation (i.e., the licensed band) for UL transmissions only; that is the licensed band is limited to UL transmissions only. The UL transmissions may include, for example, uplink resource allocation transmissions, uplink waveform transmissions, random access preamble transmissions, and uplink control channel (PUCCH) transmissions. In addition, the system may use unlicensed band operation (i.e., the unlicensed band) for DL transmission only; that is the unlicensed band is limited to DL transmissions only. The DL transmissions may include, for example, discovery reference signal (DRS) transmissions, downlink control channel (PDCCH) transmissions, and downlink data channel (PDSCH) transmissions. The limitations may be indicated by RRC or other higher-layer signaling.

[0036] Other embodiments, however, may not limit both UL and DL transmissions to a particular band. FIG. 4 illustrates an NR cell using unlicensed band DL transmissions and licensed band UL transmissions in accordance with some embodiments. In the embodiment shown in FIG. 4, a supplementary uplink (SUL) structure may be introduced to support UL transmissions only using the licensed band while the unlicensed band may be used for both uplink and downlink transmissions. The SUL may thus be an additional uplink band configured for the cell, thereby allowing the cell to choose the uplink band to be either the SUL band or the non-SUL band depending on the cell’s control. If the licensed band is configured as the SUL and the unlicensed band is configured as a regular DL/UL link, then the system may provide the uplink configuration for the SUL band to a UE and the UE can transmit uplink signals based on the configuration of the licensed SUL band.

[0037] In some embodiments, assuming SUL operation is used for supporting licensed band operation for the uplink transmission, the regular DL and UL band can be based on unlicensed band. However, if uplink

transmissions can be supported by SUL, then it may be beneficial to utilize the licensed SUL band for uplink as much as possible and use the unlicensed band for the downlink operation only since uplink transmissions may be more challenging in the unlicensed band compared to the licensed band from the perspective of government regulations. Therefore, in some circumstances, a cell may indicate to a UE to always use SUL band for its uplink transmissions.

[0038] In Rel-15, if SUL is configured, then the physical random access

Channel (PRACH) can be configured both for SUL and regular UL.

Transmission of the PRACH may be conditioned on SSB signals sent periodically by the cell in the unlicensed band. Specifically, the UE may be able to select which band it will use for the PRACH transmission depending on the Synchronization Signal Block - Reference Signal Received Power (SSB-RSRP) - that is, the RSRP of reference signals carried by the SSB. If the SSB-RSRP is higher than a pre-configured RSRP threshold, the UE may determine that the regular unlicensed band is to be used for PRACH transmission. Otherwise, if the SSB-RSRP is lower than pre-configured RSRP threshold, the UE may determine that the SUL band should be used for PRACH transmissions. This may be implemented in the rsrp-ThresholdSSB-SUL parameter of the PRACH configuration information element (E), in which the SSB-RSRP threshold may be provided as shown below:

RACH-ConfigCommon ::= SEQUENCE {

rach-ConfigGeneric RACH-ConfigGeneric,

totalNumberOfRA-Pre ambles INTEGER (1..63) OPTIONAL, - Need S ssb-perRACH-OccasionAndCB-PreamblesPerSSB CHOICE { oneEighth ENUMERATED

{n4,n8,nl2,nl6,n20,n24,n28,n32,n36,n40,n44,n48,n52,n56,n60,n64},

oneFourth ENUMERATED

{n4,n8,nl2,nl6,n20,n24,n28,n32,n36,n40,n44,n48,n52,n56,n60,n64},

oneHalf ENUMERATED

{n4,n8,nl2,nl6,n20,n24,n28,n32,n36,n40,n44,n48,n52,n56,n60,n64},

one ENUMERATED

{n4,n8,nl2,nl6,n20,n24,n28,n32,n36,n40,n44,n48,n52,n56,n60,n64},

two ENUMERATED {n4,n8,nl2,nl6,n20,n24,n28,n32}, four INTEGER (L.16),

eight INTEGER (L.8),

sixteen INTEGER (L.4)

} OPTIONAL, - Need M

groupBconfigured SEQUENCE {

ra-Msg3 SizeGroupA ENUMERATED {b56, bl44, b208, b256, b282, b480, b640,

b800, blOOO, b72, spare6, spare5,spare4, spare3, spare2, spare 1 },

messagePowerOffsetGroupB ENUMERATED { minusinfinity, dBO, dB5, dB8, dB 10, dB 12, dB 15, dB 18},

numberOfRA-PreamblesGroupA INTEGER (1..64)

} OPTIONAL, - Need R

ra-ContentionResolutionTimer ENUMERATED { sf8, sfl6, sf24, sl32, sf40, sf48, sf56, sf64},

rsrp-ThresholdS SB RSRP-Range OPTIONAL, - Need R

rsrp-ThresholdS SB -SUL RSRP-Range OPTIONAL, - Cond SUL

prach-RootSequencelndex CHOICE {

1839 INTEGER (0..837),

1139 INTEGER (0..137)

},

msgl-SubcamerSpacing SubcamerSpacing OPTIONAL, — Cond L139Need

S

restrictedSetConfig ENUMERATED (unrestrictedSet, restrictedSetTypeA, restrictedSetTypeB } ,

msg3-transformPrecoder ENUMERATED {enabled} OPTIONAL, — Need R

} [0039] As discussed above, it can be beneficial for all UEs in a cell to only use the SUL band for uplink transmission. Further measures may be taken to permit the cell to always support the use of the SUL band for PRACH transmission (that is, for PRACH transmission to exclusively use the SUL band rather than the regular band). Such measures may, for example, include the use of an IE/parameter inside the PRACH configuration indicating that the UE is to always use the SUL band for PRACH transmissions regardless of the SSB- RSRP. In other embodiments, UL transmissions other than the PRACH transmissions may be provided RRC signaling that indicates the same or a different SSB-RSRP (or other) threshold to trigger UL transmission on the licensed band.

[0040] In some embodiments, assuming SUL operation is used for supporting licensed band for the uplink transmission, the regular DL and UL band can be based on the unlicensed band. In Rel-15, if SUL operation is configured, a cell can allocate a UL resource for a UE using a physical downlink control channel (PDCCH) formed in accordance with a particular downlink control information (DCI) format. The particular DCI format can indicate whether the UE has to use SUL band or regular DL/UL band using an UL/SUL indicator (also called a licensed band/unlicensed band indicator).

[0041] DCI formats can be defined differently depending on whether the target uplink band is the unlicensed band or the licensed band since the basic resource allocation mechanisms are different between the licensed band and the unlicensed band. In some embodiments, contiguous resource allocation can be used for the licensed band while block interlaced resource allocation can be used for uplink transmissions in the unlicensed band. In addition, other DCI information fields can be different between the licensed uplink band and unlicensed uplink band. These fields may include, for example, Hybrid automatic repeat request (HARQ) process number and time domain resource assignment. Thus, depending on whether the target uplink band is the unlicensed band or licensed band, the number of bits for the DCI format can be different. This thus means that the UE can interpret the DCI information based on the information of the UL/SUL indicator. Depending on the information of the UL/SUL indicator, the DCI size can be also determined and the

corresponding DCI information can be determined.

[0042] In some embodiments, assuming SUL operation is used for supporting use of the licensed band for the uplink transmission, the regular DL band can be based on the unlicensed band. In order to limit the uplink transmission to only use the SUL band, a cell may configure UEs in this manner - i.e., to set that only the SUL band is to be used for the uplink transmission. If such pre-configuration is performed, then the cell can avoid the transmission of the UL/SUL indicator and the UE can interpret that the DCI for uplink transmission is for the SUL band by default.

[0043] In some embodiments, the UE and/or base station (eNB/gNB) may be configured to perform one or more processes, techniques, or methods as described herein, or portions thereof. One such process is depicted in FIG. 5, which shows a method of communication of a UE in accordance with some embodiments. As shown, the process may include the UE at operation 502 receiving or processing configuration information for an unlicensed band to be used by the UE for communication on a cell of a wireless cellular network. At operation 504, the UE may use the unlicensed band for downlink communication on the cell. At operation 506, the UE may receive or process configuration information for a licensed band to be used by the UE as a SUL resource for uplink communication on the cell of the wireless cellular network. In some embodiments, operation 502 and 506 may occur in the same communication.

[0044] FIG. 6 illustrates a method of communication of a base station in accordance with some embodiments. At operation 602, the base station may transmit or cause to transmit, to a UE, configuration information for an unlicensed band to be used by the UE for communication on a cell of a wireless cellular network. At operation 604, the base station may use the unlicensed band for downlink transmissions to the UE on the cell. At operation 606, the base station may transmit or cause to transmit configuration information for a licensed band to be used by the UE as a SUL resource for uplink communication on the cell of the wireless cellular network. As above, in some embodiments, operation 602 and 606 may occur in the same communication.

[0045] Although an aspect has been described with reference to specific example aspects, it will be evident that various modifications and changes may be made to these aspects without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof show, by way of illustration, and not of limitation, specific aspects in which the subject matter may be practiced. The aspects illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other aspects may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various aspects is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

[0046] The Abstract of the Disclosure is provided to comply with 37

C.F.R. § 1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single aspect for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed aspects require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed aspect. Thus, the following claims are hereby incorporated into the Detailed

Description, with each claim standing on its own as a separate aspect.

Claims

CLAIMS What is claimed is:

1. An apparatus of a user equipment (UE), the apparatus comprising:

processing circuitry configured to:

determine, based on control signaling from a fifth generation (5G) nodeB (gNB) on an unlicensed band, a condition for use of a licensed band for uplink transmissions to the gNB, the licensed band reserved for uplink transmissions to the gNB; and

encode, in response to a determination that the condition is not met, an uplink transmission to the gNB on the licensed band; and a memory configured to store the condition.

2. The apparatus of claim 1, wherein the processing circuitry is further configured to:

determine, from the control signaling, that the unlicensed band is reserved for downlink transmissions and that uplink transmissions to the gNB are limited to the licensed band.

3. The apparatus of claim 1, wherein the processing circuitry is further configured to:

determine, from the control signaling, that the unlicensed band is to be used for uplink transmissions when the condition is met.

4. The apparatus of claim 3, wherein:

the control signaling is radio resource control (RRC) signaling, and the condition comprises Synchronization Signal Block - Reference Signal Received Power (SSB-RSRP) meeting a threshold indicated in the RRC signaling.

5. The apparatus of claim 4, wherein the RRC signaling indicates in a RACH-ConfigCommon information element (IE) that a Physical Random Access Channel (PRACH) transmission is to be transmitted on the licensed band if the SSB-RSRP is lower than the indicated threshold.

6. The apparatus of claim 5, wherein:

the indicated threshold is set as a highest or lowest value as all UEs choose the licensed band for the PRACH transmission.

7. The apparatus of claim 3, wherein:

the control signaling is radio resource control (RRC) signaling, and the RRC signaling indicates in a RACH-ConfigCommon information element (IE) that a Physical Random Access Channel (PRACH) transmission is to be transmitted on the licensed band independent of the SSB-RSRP.

8. The apparatus of claim 3, wherein:

the control signaling is radio resource control (RRC) signaling, and the processing circuitry is further configured to:

decode a Physical Downlink Control Channel (PDCCH) transmission from the gNB on the unlicensed band after reception of the control signaling, the PDCCH transmission having a downlink control information (DCI) format, the DCI format comprising a licensed band/unlicensed band indicator that indicates which of the licensed band and unlicensed band the UE is to use for uplink transmissions, and

disregard the condition based on the licensed band/unlicensed band indicator.

9. The apparatus of claim 8, wherein the processing circuitry is further configured to:

interpret the DCI format based on the licensed band/unlicensed band indicator, a size of the DCI format indicated by the licensed band/unlicensed band indicator.

10. The apparatus of claim 3, wherein: the control signaling is radio resource control (RRC) signaling, and the processing circuitry is further configured to:

decode a Physical Downlink Control Channel (PDCCH) transmission from the gNB on the unlicensed band after reception of the control signaling, the PDCCH transmission having a downlink control information (DCI) format, and

determine if the DCI format comprises a licensed band/unlicensed band indicator that indicates which of the licensed band and unlicensed band the UE is to use for uplink transmissions, and, in response to a determination that the DCI does not include the licensed band/unlicensed band indicator, default to use of the licensed band for uplink

transmissions.

11. The apparatus of claim 3, wherein:

the control signaling is a licensed band/unlicensed band indicator that indicates which of the licensed band and unlicensed band the UE is to use for uplink transmissions, and

the processing circuitry is further configured to decode a Physical Downlink Control Channel (PDCCH) transmission from the gNB on the unlicensed band after reception of the control signaling, the PDCCH

transmission having a downlink control information (DCI) format, the DCI format comprising the licensed band/unlicensed band indicator.

12. An apparatus of a 5^th generation NodeB (gNB), the apparatus

comprising:

processing circuitry configured to:

determine if control signaling, indicating if uplink transmissions to the gNB are to be provided on a licensed band, is to be transmitted to a user equipment (UE) on an unlicensed band, the licensed band reserved for uplink transmissions to the gNB; and decode an uplink transmission from the UE on the licensed band in response to transmission of the control signaling indicating that uplink transmissions are to be provided to the gNB on the licensed band; and a memory configured to store the control signaling.

13. The apparatus of claim 12, wherein:

the unlicensed band is reserved for downlink transmissions and the uplink transmissions are limited to the licensed band independent of the control signaling.

14. The apparatus of claim 12, wherein the processing circuitry is further configured to:

indicate, in the control signaling, a condition that the unlicensed band is to be used for uplink transmissions when Synchronization Signal Block - Reference Signal Received Power (SSB-RSRP) meets an indicated threshold in the control signaling.

15. The apparatus of claim 14, wherein:

the control signaling is radio resource control (RRC) signaling, and the RRC signaling indicates in a RACH-ConfigCommon information element (IE) that a Physical Random Access Channel (PRACH) transmission is to be transmitted on the licensed band if the SSB-RSRP is lower than the indicated threshold.

16. The apparatus of claim 14, wherein the processing circuitry is further configured to:

encode, for transmission to the UE, a Physical Downlink Control Channel (PDCCH) transmission having a downlink control information (DCI) format, the DCI format comprising a licensed band/unlicensed band indicator that indicates which of the licensed band and unlicensed band the UE is to use for uplink transmissions, the band/unlicensed band indicator overriding the condition.

17. The apparatus of claim 16, wherein:

a size of the DCI format is indicated by the licensed band/unlicensed band indicator.

18. The apparatus of claim 11, wherein at least one of:

the processing circuitry is further configured to determine whether to include a licensed band/unlicensed band indicator that indicates which of the licensed band and unlicensed band the UE is to use for uplink transmissions in downlink control information (DCI), exclusion of the licensed band/unlicensed band indicator in the DCI indicating default to use of the licensed band for uplink transmission, or

the control signaling is radio resource control (RRC) signaling, and the RRC signaling indicates in a RACH-ConfigCommon information element (IE) that a Physical Random Access Channel (PRACH) transmission is limited to be transmitted on the licensed band.

19. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of a user equipment (UE), the one or more processors to configure the UE to, when the instructions are executed:

determine, from control signaling received from a fifth generation (5G) nodeB (gNB) on an unlicensed band, the control signaling indicating uplink transmissions are to be provided to the gNB on a licensed band that is reserved for uplink transmissions, the determination based on Synchronization Signal Block - Reference Signal Received Power (SSB-RSRP) meeting an indicated threshold if the control signaling is radio resource control (RRC) signaling and based on a licensed band/unlicensed band indicator in a downlink control information (DCI) if the control signaling is a Physical Downlink Control Channel (PDCCH) transmission; and

transmit, to the gNB, an uplink transmission on one of the unlicensed and licensed band indicated by the control signaling.

20. The medium of claim 19, wherein the one or more processors further configure the UE to, when the instructions are executed:

ignore whether the SSB-RSRP meets the indicated threshold if the DCI contains the licensed band/unlicensed band indicator.