Patent Publication Number: US-2023164744-A1

Title: Bandwidth part and resource bandwidth switching in wireless communications

Description:
CROSS REFERENCE 
     The present application is a 371 national stage filing of International PCT Application No. PCT/US2021/035153 by ABOTABL et al. entitled “BANDWIDTH PART AND RESOURCE BANDWIDTH SWITCHING IN WIRELESS COMMUNICATIONS,” filed Jun. 1, 2021; and claims priority to Greek Patent Application No. 20200100299 by ABOTABL et al. entitled “BANDWIDTH PART AND RESOURCE BANDWIDTH SWITCHING IN WIRELESS COMMUNICATIONS,” filed Jun. 2, 2020, each of which is assigned to the assignee hereof, and each of which is expressly incorporated by reference in its entirety herein. 
    
    
     FIELD OF TECHNOLOGY 
     The following relates generally to wireless communications and more specifically to bandwidth part and resource bandwidth switching in wireless communications. 
     BACKGROUND 
     Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). 
     Some wireless communications systems may include communication devices, such as UEs and base stations that may support duplex communications, such as half-duplex communications and full-duplex communications. The UEs and the base stations may also support various bandwidth parts (BWPs) for half-duplex communications and full-duplex communications. The UEs and the base stations may, in some cases, also experience latency with the duplex communications as a result of switching BWPs. As demand for communication efficiency increases, it may be desirable for the UEs and the base stations to provide improvements to BWP operations to support enhanced reliability and reduced latency duplex communications. 
     SUMMARY 
     Various aspects of the described techniques relate to configuring a communication device, such as a user equipment (UE), to support duplex communications over one or multiple resource bandwidths within one or multiple bandwidth parts (BWPs) of a total available channel bandwidth. A BWP may be a portion of a radio frequency spectrum band that the UE may use for downlink communications, or uplink communications, or both. In some cases, the UE may initiate a random access procedure, in which a random access message is transmitted to a base station. In order to provide for reliable communication of random access requests, the base station (or other network component) may configure one or more random access occasions, which may include time domain resources and frequency domain resources in which the base station monitors for random access requests. 
     In some cases, the UE may be configured with an active BWP and resource bandwidth that does not contain any random access occasions, and during a random access procedure the UE may switch to an initial resource bandwidth for transmission of the random access request, where the initial resource bandwidth is configured with one or more random access occasions. In some cases, a medium access control (MAC) entity at the UE may perform the resource bandwidth switching for the random access procedure. The described techniques may, as a result, include features for improvements to resource bandwidth and BWP operations when switching resource bandwidths or BWPs and, in some examples, may promote high reliability and low latency duplex communications, among other benefits. 
     A method of wireless communication at a UE is described. The method may include receiving, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, determining to transmit a random access request to the base station and that an active resource bandwidth for communications with the base station has an absence of random access occasions, selecting, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth, and transmitting the random access request in the selected first random access occasion. 
     An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, determine to transmit a random access request to the base station and that an active resource bandwidth for communications with the base station has an absence of random access occasions, select, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth, and transmit the random access request in the selected first random access occasion. 
     Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, determining to transmit a random access request to the base station and that an active resource bandwidth for communications with the base station has an absence of random access occasions, selecting, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth, and transmitting the random access request in the selected first random access occasion. 
     A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to receive, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, determine to transmit a random access request to the base station and that an active resource bandwidth for communications with the base station has an absence of random access occasions, select, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth, and transmit the random access request in the selected first random access occasion. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the initial resource bandwidth spans entire frequency domain bandwidth of the associated bandwidth part. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the two or more bandwidth parts are configured for full-duplex communications between the UE and the base station, and where the initial resource bandwidth spans a portion of an associated bandwidth part of the two or more bandwidth parts that is compatible with half-duplex communications. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the receiving may include operations, features, means, or instructions for receiving RRC signaling that configures the two or more bandwidth parts, the two or more resource bandwidths, and one or more initial resource bandwidths within one or more of the bandwidth parts. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the initial resource bandwidth is configured within one or more uplink bandwidth parts of the two or more bandwidth parts. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the initial resource bandwidth has a bandwidth identification within a corresponding uplink bandwidth part of the one or more uplink bandwidth parts, and where a corresponding downlink resource bandwidth has a corresponding downlink resource bandwidth identification within a downlink bandwidth part. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the initial resource bandwidth spans contiguous or disjoint frequency domain resources of the associated bandwidth part. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths, none of which are configured as the initial resource bandwidth. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths that are configured with one or more random access occasions. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the determining may include operations, features, means, or instructions for determining, by a medium access control (MAC) entity at the UE, to transmit the random access request for communications with the base station. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining to transmit the random access request using the active resource bandwidth when the active resource bandwidth has one or more random access occasions. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the selecting further may include operations, features, means, or instructions for switching the active resource bandwidth from a first uplink resource bandwidth to the initial resource bandwidth based on the first uplink resource bandwidth having an absence of random access occasions. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the selecting further may include operations, features, means, or instructions for switching a downlink resource bandwidth to correspond with the initial resource bandwidth. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the selecting further may include operations, features, means, or instructions for determining that the active resource bandwidth within an active uplink bandwidth part is not configured with a random access occasion, and that an initial resource bandwidth of the active uplink bandwidth part is not configured or is configured without a random access occasion, and switching the active uplink bandwidth part to an initial uplink bandwidth part that is configured with the initial resource bandwidth that includes the first random access occasion. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, an active downlink bandwidth part corresponds to the initial uplink bandwidth part, and an active downlink resource bandwidth corresponds to the initial resource bandwidth, subsequent to the switching. 
     A method of wireless communication at a base station is described. The method may include transmitting, to a UE, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, configuring the UE with an active resource bandwidth for communications with the base station that has an absence of random access occasions, and monitoring the one or more random access occasions of the initial resource bandwidth for a random access request from the UE. 
     An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit, to a UE, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, configure the UE with an active resource bandwidth for communications with the base station that has an absence of random access occasions, and monitor the one or more random access occasions of the initial resource bandwidth for a random access request from the UE. 
     Another apparatus for wireless communication at a base station is described. The apparatus may include means for transmitting, to a UE, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, configuring the UE with an active resource bandwidth for communications with the base station that has an absence of random access occasions, and monitoring the one or more random access occasions of the initial resource bandwidth for a random access request from the UE. 
     A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to transmit, to a UE, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, configure the UE with an active resource bandwidth for communications with the base station that has an absence of random access occasions, and monitor the one or more random access occasions of the initial resource bandwidth for a random access request from the UE. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the initial resource bandwidth spans entire frequency domain bandwidth of the associated bandwidth part. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the two or more bandwidth parts are configured for full-duplex communications between the UE and the base station, and where the initial resource bandwidth spans a portion of an associated bandwidth part of the two or more bandwidth parts that is compatible with half-duplex communications. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the transmitting may include operations, features, means, or instructions for transmitting RRC signaling that configures the two or more bandwidth parts, the two or more resource bandwidths, and one or more initial resource bandwidths within one or more of the bandwidth parts. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the initial resource bandwidth is configured within one or more uplink bandwidth parts of the two or more bandwidth parts. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the initial resource bandwidth has a bandwidth identification within a corresponding uplink bandwidth part of the one or more uplink bandwidth parts, and where a corresponding downlink resource bandwidth has a corresponding downlink resource bandwidth identification within a downlink bandwidth part. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the initial resource bandwidth spans contiguous or disjoint frequency domain resources of the associated bandwidth part. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths, none of which are configured as the initial resource bandwidth. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths that are configured with one or more random access occasions. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the random access request is transmitting by the UE using the active resource bandwidth when the active resource bandwidth has one or more random access occasions. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the UE switches the active resource bandwidth from a first uplink resource bandwidth to the initial resource bandwidth based on the first uplink resource bandwidth having an absence of random access occasions. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a downlink resource bandwidth for a random access response transmission corresponds with the initial resource bandwidth. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the initial resource bandwidth is in an initial bandwidth part that is configured with random access occasions, and where the active resource bandwidth of the UE is not configured with a random access occasion, and an active uplink bandwidth part of the UE is not configured with an initial resource bandwidth with a random access occasion. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, an active downlink bandwidth part corresponds to the initial uplink bandwidth part, and an active downlink resource bandwidth corresponds to the initial resource bandwidth, subsequent to the switching. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates an example of a system for wireless communications that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIG.  2    illustrates an example of a wireless communications system that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIGS.  3 A through  3 C  illustrate examples of wireless communications systems that support bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIGS.  4 A and  4 B  illustrate examples of full duplex configurations that support bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIG.  5    illustrates an example of a radio frequency spectrum subband configuration that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIG.  6    illustrates an example of a BWP and resource bandwidth configuration that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIGS.  7  and  8    show block diagrams of devices that support bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIG.  9    shows a block diagram of a communications manager that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIG.  10    shows a diagram of a system including a device that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIGS.  11  and  12    show block diagrams of devices that support bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIG.  13    shows a block diagram of a communications manager that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIG.  14    shows a diagram of a system including a device that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
         FIGS.  15  through  18    show flowcharts illustrating methods that support bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Some wireless communications systems may provide for communication between devices, such as a user equipment (UE) and base station, for example. The UE and the base station may support duplex communications, such as half-duplex communications and full-duplex communications. The UE and the base station may also support various bandwidth parts (BWPs) for the half-duplex communications and the full-duplex communications, where each BWP is a portion of an available bandwidth for wireless communications. Each BWP may be a contiguous set of resources that is configured via radio resource control (RRC) signaling, and thus BWP switching is a relatively slow process that is associated with RRC reconfiguration of BWPs that may take a relatively long time to complete (e.g., due to signaling associated with RRC configuration/reconfiguration and associated communications between the UE and the base station). Further, BWPs may be defined such that they span contiguous frequency domain resources. 
     In some cases, a BWP may be configured with multiple resource bandwidths, within one or more BWPs. Each resource bandwidth may span an entire BWP, or a portion of a BWP. Examples of the resource bandwidth may include a sub-bandwidth part (sub-BWP). Further, a resource bandwidth may be non-contiguous in the frequency domain within a configured BWP. In some cases, a UE may be configured to receive a BWP configuration defining a set of resource bandwidths for one or multiple BWPs. Each resource bandwidth may define time and frequency resources for one or multiple BWPs allocated for downlink communications or uplink communications. The UE may determine that at least one resource bandwidth in the set is an initial resource bandwidth (which may also be referred to as a master resource bandwidth, or a default resource bandwidth) to be used for the downlink communications, or the uplink communications, or both. In some examples, the initial resource bandwidth is used for communications, for example, if the UE does not determine or has not received any indication about which resource bandwidth to use for a given BWP (e.g., if a BWP or resource bandwidth has not been activated at the UE). In other words, the initial resource bandwidth may become an active resource bandwidth for a BWP unless the UE is signaled a particular resource bandwidth to use for the BWP (e.g., signaled by a base station). Therefore, the UE may communicate with a base station using the initial resource bandwidth or a particular active resource bandwidth signaled to the UE. 
     The UE may also be configured with one or more random access occasions, which may be used to transmit a random access request to the base station as part of a random access procedure. In some cases, a portion (e.g., only a portion) of the configured BWPs, a portion of the resource bandwidths, or combinations thereof, may be configured with random access occasions. In some cases, the initial BWP and one or more initial resource bandwidths (e.g., one initial resource bandwidth for each configured BWP), may be configured with random access occasions, such that the UE may be able to transmit a random access request in the event that no active BWP or resource bandwidth is present. In some cases, the initial resource bandwidth is configured in radio resource control (RRC) signaling from the base station. Thus, in the event that a medium access control (MAC) entity at the UE determines that a random access request is to be transmitted, the MAC entity may switch the resource bandwidth to the initial resource bandwidth in the event that the active resource bandwidth does not have any configured random access occasions. In some cases, in the event that a MAC entity at the UE determines that a random access request is to be transmitted, the MAC entity may switch the BWP to the initial BWP in the event that the active BWP does not have any configured random access occasions. 
     In some cases, the initial resource bandwidth may have a defined resource bandwidth identification (e.g., a resource bandwidth ID of 0 or 1), and any configured resource bandwidth having the defined resource bandwidth identification may be considered to be an initial resource bandwidth. The random access occasions in such cases are configured in uplink resource bandwidths, which may be configured separately from downlink BWPs and downlink resource bandwidths. In some cases, the corresponding resource bandwidth in the downlink BWP has the resource bandwidth identification as the initial bandwidth in the corresponding uplink BWP. The initial resource bandwidth may span the entire bandwidth of the associated BWP, may span a portion of the bandwidth of the BWP, and can be disjoint or include non-contiguous frequency-domain resources. In some cases, resource bandwidths may include one or more resource bandwidths that are designed for half-duplex mode operations at the UE. In some cases, an uplink BWP configured with multiple resource bandwidths might have none of the resource bandwidth is initial resource bandwidth (i.e., the initial resource bandwidth is not configured), an initial resource bandwidth that is configured, or multiple resource bandwidths that are configured with random access occasions. 
     In some cases, if the MAC entity initiates a random access procedure, it may be determined whether a currently active resource bandwidth is configured with random access occasions. If the currently active resource bandwidth does have one or more random access occasions configured, the UE does not switch the resource bandwidth or the BWP, and a random access request may be transmitted in one of the configured random access occasions of the active resource bandwidth. If the active resource bandwidth of the UE is not configured with any random access occasions, the MAC entity at the UE may switch the resource bandwidth to the initial resource bandwidth. In cases where the active resource bandwidth is not configured with random access occasions and the initial resource bandwidth is not configured in the active BWP, or if the initial resource bandwidth of the active BWP is configured without random access occasions, the UE switches the active BWP to the initial uplink BWP, and the initial resource bandwidth is selected from the initial uplink BWP. The initial resource bandwidth in the initial uplink BWP will become the active resource bandwidth. 
     For downlink communications, the UE may or may not switch the active resource bandwidth, based on which downlink BWP and downlink resource bandwidth is active at the UE. For example, if the active resource bandwidth includes resources that are to be monitored for a random access response as part of a random access configuration, the UE will not switch the active resource bandwidth or BWP. If the UE switches the active downlink resource bandwidth, it may be switched to the resource bandwidth with an identification that corresponds to the initial resource bandwidth identification, which the base station may use to transmit the random access response. 
     Aspects of the subject matter described in this disclosure may be implemented to realize one or more of the following potential improvements, among others. The techniques employed by UEs may provide benefits and enhancements to the operation of the UEs. For example, operations performed by the UEs may provide improvements to BWP and resource bandwidth operations. In some examples, configuring the UEs to support an initial resource bandwidth for a BWP may provide flexibility for duplex communications at the UEs. In some other examples, configuring the UEs to support an initial resource bandwidth for random access communications may provide improvements to power consumption, spectral efficiency, and, in some examples, may promote high reliability and low latency duplex communications, among other benefits. 
     Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to duplex communications over BWPs. 
       FIG.  1    illustrates an example of a wireless communications system  100  that supports bandwidth part and resource bandwidth switching in accordance with aspects of the present disclosure. The wireless communications system  100  may include one or more base stations  105 , one or more UEs  115 , and a core network  130 . In some examples, the wireless communications system  100  may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system  100  may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof. 
     The base stations  105  may be dispersed throughout a geographic area to form the wireless communications system  100  and may be devices in different forms or having different capabilities. The base stations  105  and the UEs  115  may wirelessly communicate via one or more communication links  125 . Each base station  105  may provide a coverage area  110  over which the UEs  115  and the base station  105  may establish one or more communication links  125 . The coverage area  110  may be an example of a geographic area over which a base station  105  and a UE  115  may support the communication of signals according to one or more radio access technologies. 
     The UEs  115  may be dispersed throughout a coverage area  110  of the wireless communications system  100 , and each UE  115  may be stationary, or mobile, or both at different times. The UEs  115  may be devices in different forms or having different capabilities. Some example UEs  115  are illustrated in  FIG.  1   . The UEs  115  described herein may be able to communicate with various types of devices, such as other UEs  115 , the base stations  105 , or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), as shown in  FIG.  1   . 
     The base stations  105  may communicate with the core network  130 , or with one another, or both. For example, the base stations  105  may interface with the core network  130  through one or more backhaul links  120  (e.g., via an S1, N2, N3, or other interface). The base stations  105  may communicate with one another over the backhaul links  120  (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations  105 ), or indirectly (e.g., via core network  130 ), or both. In some examples, the backhaul links  120  may be or include one or more wireless links. One or more of the base stations  105  described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology. 
     A UE  115  may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE  115  may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UE  115  may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples. The UEs  115  described herein may be able to communicate with various types of devices, such as other UEs  115  that may sometimes act as relays as well as the base stations  105  and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in  FIG.  1   . 
     The UEs  115  and the base stations  105  may wirelessly communicate with one another via one or more communication links  125  over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links  125 . For example, a carrier used for a communication link  125  may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP)) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system  100  may support communication with a UE  115  using carrier aggregation or multi-carrier operation. A UE  115  may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers. 
     In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)) and may be positioned according to a channel raster for discovery by the UEs  115 . A carrier may be operated in a standalone mode where initial acquisition and connection may be conducted by the UEs  115  via the carrier, or the carrier may be operated in a non-standalone mode where a connection is anchored using a different carrier (e.g., of the same or a different radio access technology). 
     The communication links  125  shown in the wireless communications system  100  may include uplink transmissions from a UE  115  to a base station  105 , or downlink transmissions from a base station  105  to a UE  115 . Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode). A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system  100 . For example, the carrier bandwidth may be one of a number of determined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)). Devices of the wireless communications system  100  (e.g., the base stations  105 , the UEs  115 , or both) may have hardware configurations that support communications over a particular carrier bandwidth or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system  100  may include base stations  105  or UEs  115  that support simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE  115  may be configured for operating over portions (e.g., a sub-band, a BWP) or all of a carrier bandwidth. 
     Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may include one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource elements that a UE  115  receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE  115 . A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams), and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE  115 . 
     One or more numerologies for a carrier may be supported, where a numerology may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs having the same or different numerologies. In some examples, a UE  115  may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time and communications for the UE  115  may be restricted to one or more active BWPs. 
     The wireless communications system  100  may support duplex communications, such as half-duplex communications and full-duplex communications. The wireless communications system  100  may support the duplex communication over various BWPs. The base stations  105  and the UEs  115  may experience interference issues due to the duplex communications, which may impact a reliability and a latency of the wireless communications system  100 . The base stations  105  and the UEs  115  may experience a delay in the duplex communications due to a BWP switching by the base stations  105  and the UEs  115 . As demand for communication efficiency increases, it may be desirable for the wireless communications system  100  to provide improvements to BWP operations to support high reliability and low latency duplex communications, among other examples. 
     A UE  115  may receive a BWP configuration defining a set of resource bandwidths for the one or multiple BWPs. Each resource bandwidth may define time and frequency resources associated with the one or multiple BWPs allocated for downlink communications or uplink communications. The resource bandwidths may thus accommodate disjoint bandwidth allocation for duplex communications, such as full-duplex communications supporting both downlink communications and uplink communications. The UE  115  may determine that at least one resource bandwidth in the set is a master resource bandwidth (also referred to as a default resource bandwidth) used for the downlink communications or the uplink communications, or both. 
     For example, the master resource bandwidth may function as a default resource bandwidth for the UE  115 , if the UE  115  does not know (e.g., a base station  105  does not explicitly signal the UE  115  to use a particular resource bandwidth) which resource bandwidth to use for a BWP. The master resource bandwidth may also provide flexibility for the UE  115  when switching BWPs in which the master resource bandwidth becomes an active resource bandwidth, unless the UE  115  is explicitly signaled a particular resource bandwidth. The described techniques may, as a result, include features for improvements to BPW operations when switching BWPs and, in some examples, may promote high reliability and low latency duplex communications over different BWPs in the wireless communications system  100 , among other benefits. 
     The time intervals for the base stations  105  or the UEs  115  may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T s =1/(Δf max ·N f ) seconds, where Δf max  may represent the maximum supported subcarrier spacing, and N f  may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023). 
     Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of slots. Alternatively, each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing. Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). In some wireless communications systems  100 , a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N f ) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation. A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system  100  and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system  100  may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)). 
     Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs  115 . For example, one or more of the UEs  115  may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs)) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs  115  and UE-specific search space sets for sending control information to a specific UE  115 . 
     Each base station  105  may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a base station  105  (e.g., over a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or others). In some examples, a cell may also refer to a geographic coverage area  110  or a portion of a geographic coverage area  110  (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the base station  105 . For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with geographic coverage areas  110 , among other examples. 
     A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs  115  with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered base station  105 , as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs  115  with service subscriptions with the network provider or may provide restricted access to the UEs  115  having an association with the small cell (e.g., the UEs  115  in a closed subscriber group (CSG), the UEs  115  associated with users in a home or office). A base station  105  may support one or multiple cells and may also support communications over the one or more cells using one or multiple component carriers. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that may provide access for different types of devices. 
     In some examples, a base station  105  may be movable and therefore provide communication coverage for a moving geographic coverage area  110 . In some examples, different geographic coverage areas  110  associated with different technologies may overlap, but the different geographic coverage areas  110  may be supported by the same base station  105 . In other examples, the overlapping geographic coverage areas  110  associated with different technologies may be supported by different base stations  105 . The wireless communications system  100  may include, for example, a heterogeneous network in which different types of the base stations  105  provide coverage for various geographic coverage areas  110  using the same or different radio access technologies. 
     The wireless communications system  100  may support synchronous or asynchronous operation. For synchronous operation, the base stations  105  may have similar frame timings, and transmissions from different base stations  105  may be approximately aligned in time. For asynchronous operation, the base stations  105  may have different frame timings, and transmissions from different base stations  105  may, in some examples, not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations. 
     Some UEs  115 , such as MTC or IoT devices, may be low cost or low complexity devices and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication). M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station  105  without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application program that makes use of the information or presents the information to humans interacting with the application program. Some UEs  115  may be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging. 
     Some UEs  115  may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously). In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs  115  include entering a power saving deep sleep mode when not engaging in active communications, operating over a limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs  115  may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs)) within a carrier, within a guard-band of a carrier, or outside of a carrier. 
     The wireless communications system  100  may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system  100  may be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications. The UEs  115  may be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission critical functions). Ultra-reliable communications may include private communication or group communication and may be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT), mission critical video (MCVideo), or mission critical data (MCData). Support for mission critical functions may include prioritization of services, and mission critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low-latency may be used interchangeably herein. 
     In some examples, a UE  115  may also be able to communicate directly with other UEs  115  over a device-to-device (D2D) communication link  135  (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs  115  utilizing D2D communications may be within the geographic coverage area  110  of a base station  105 . Other UEs  115  in such a group may be outside the geographic coverage area  110  of a base station  105  or be otherwise unable to receive transmissions from a base station  105 . In some examples, groups of the UEs  115  communicating via D2D communications may utilize a one-to-many (1:M) system in which each UE  115  transmits to every other UE  115  in the group. In some examples, a base station  105  facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between the UEs  115  without the involvement of a base station  105 . 
     In some systems, the D2D communication link  135  may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs  115 ). In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations  105 ) using vehicle-to-network (V2N) communications, or with both. 
     The core network  130  may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network  130  may be an evolved packet core (EPC) or 5G core (5GC), which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs  115  served by the base stations  105  associated with the core network  130 . User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to the network operators IP services  150 . The operators IP services  150  may include access to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or a Packet-Switched Streaming Service. 
     Some of the network devices, such as a base station  105 , may include subcomponents such as an access network entity  140 , which may be an example of an access node controller (ANC). Each access network entity  140  may communicate with the UEs  115  through one or more other access network transmission entities  145 , which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs). Each access network transmission entity  145  may include one or more antenna panels. In some configurations, various functions of each access network entity  140  or base station  105  may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station  105 ). 
     The wireless communications system  100  may operate using one or more frequency bands (e.g., in the range of 300 megahertz (MHz) to 300 gigahertz (GHz)). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs  115  located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz. 
     The wireless communications system  100  may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band, or in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, the wireless communications system  100  may support millimeter wave (mmW) communications between the UEs  115  and the base stations  105 , and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, this may facilitate use of antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body. 
     The wireless communications system  100  may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system  100  may employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations  105  and the UEs  115  may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples. 
     A base station  105  or a UE  115  may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station  105  or a UE  115  may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station  105  may be located in diverse geographic locations. A base station  105  may have an antenna array with a number of rows and columns of antenna ports that the base station  105  may use to support beamforming of communications with a UE  115 . Likewise, a UE  115  may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port. 
     The base stations  105  or the UEs  115  may use MIMO communications to exploit multipath signal propagation and increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices. 
     Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station  105 , a UE  115 ) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation). 
     A base station  105  or a UE  115  may use beam sweeping techniques as part of beam forming operations. For example, a base station  105  may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE  115 . Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station  105  multiple times in different directions. For example, the base station  105  may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by a transmitting device, such as a base station  105 , or by a receiving device, such as a UE  115 ) a beam direction for later transmission or reception by the base station  105 . 
     Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station  105  in a single beam direction (e.g., a direction associated with the receiving device, such as a UE  115 ). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted in one or more beam directions. For example, a UE  115  may receive one or more of the signals transmitted by the base station  105  in different directions and may report to the base station  105  an indication of the signal that the UE  115  received with a highest signal quality or an otherwise acceptable signal quality. 
     In some examples, transmissions by a device (e.g., by a base station  105  or a UE  115 ) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from a base station  105  to a UE  115 ). The UE  115  may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across a system bandwidth or one or more sub-bands. The base station  105  may transmit a reference signal (e.g., a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS)), which may be precoded or unprecoded. The UE  115  may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted in one or more directions by a base station  105 , a UE  115  may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE  115 ) or for transmitting a signal in a single direction (e.g., for transmitting data to a receiving device). 
     A receiving device (e.g., a UE  115 ) may try multiple receive configurations (e.g., directional listening) when receiving various signals from the base station  105 , such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal). The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR), or otherwise acceptable signal quality based on listening according to multiple beam directions). 
     The wireless communications system  100  may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE  115  and a base station  105  or a core network  130  supporting radio bearers for user plane data. At the physical layer, transport channels may be mapped to physical channels. 
     The UEs  115  and the base stations  105  may support retransmissions of data to increase the likelihood that data is received successfully. Hybrid automatic repeat request (HARQ) feedback is one technique for increasing the likelihood that data is received correctly over a communication link  125 . HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., low signal-to-noise conditions). In some examples, a device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval. 
     In some cases, communications between base stations  105  and UEs  115  may be duplex communications in which a UE  115  concurrently transmits and receives communications using a same set of time and frequency resources. As discussed herein, in some cases one or more resource bandwidths may be configured in one or more BWPs to support relatively fast switching and allow enhanced flexibility for such duplex communications. In some cases, within one or more BWPs, an initial resource bandwidth may be configured that has one or more configured random access occasions, which may be used in the event that the UE  115  is to transmit a random access request, as discussed herein. 
       FIG.  2    illustrates an example of a wireless communications system  200  that supports bandwidth part and resource bandwidth switching in accordance with aspects of the present disclosure. The wireless communications system  200  may implement aspects of the wireless communications system  100 . For example, the wireless communications system  200  may include a base station  105 - a  and a UE  115 - a , which may be examples of a base station  105  and a UE  115  as described herein. The wireless communications system  200  may support multiple radio access technologies including 4G systems such as LTE systems, LTE-A systems, or LTE-A Pro systems, and 5G systems, which may be referred to as NR systems. 
     The base station  105 - a  and the UE  115 - a  may be configured with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output communications, or beamforming, or any combination thereof. The antennas of the base station  105 - a  and the UE  115 - a  may be located within one or more antenna arrays or antenna panels, which may support multiple-input multiple-output operations or transmit or receive beamforming. For example, the base station  105 - a  antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with the base station  105 - a  may be located in diverse geographic locations. The base station  105 - a  may have an antenna array with a number of rows and columns of antenna ports that the base station  105 - a  may use to support beamforming of communications with the UE  115 - a . Likewise, the UE  115 - a  may have one or more antenna arrays that may support various multiple-input multiple-output or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via one or more antenna ports. The base station  105 - a  and the UE  115 - a  may thus be configured to support directional communications  205  (e.g., beamformed communications) using the multiple antennas. In some examples, the base station  105 - a  or the UE  115 - a  may support duplex communications  210 , such as half-duplex communications, or full-duplex communications, or both, via carriers associated with multiple carrier bandwidths over the directional communications  205 . 
     The base station  105 - a  and the UE  115 - a  may, in some cases, support subband half-duplex communications or subband full-duplex communications. The base station  105 - a  and the UE  115 - a  may support duplex communications using TDD techniques or FDD techniques. The base station  105 - a  and the UE  115 - a  may, in some cases, support TDD operations and FDD operations in an unpaired spectrum or a paired spectrum. An unpaired spectrum provides a single subband or a single band for both downlink communications and uplink communications. A paired spectrum provides a distinct subband or band for downlink communications and uplink communications. For example, the wireless communications system  200  may have a block of radio frequency spectrum in a lower frequency band and an associated block of radio frequency spectrum in an upper frequency band. 
     An arrangement of frequency bands with one band for the uplink communications and one band for the downlink communications may be referred to as paired spectrum. The UE  115 - a  may be configured for operating over portions of a radio frequency spectrum band (e.g., a bandwidth). For example, the UE  115 - a  may be configured to operate over one or multiple BWPs  215 . In some cases, when the base station  105 - a  and the UE  115 - a  are configured with multiple antenna panels, where one antenna panel may be dedicated for downlink communications and another antenna panel may be dedicated for uplink communications in an unpaired spectrum or a paired spectrum, the base station  105 - a  and the UE  115 - a  may experience self-interference when communicating over the one or multiple BWPs  215 . The self-interference may be a result of simultaneously using multiple antenna panels for uplink communications and downlink communications (e.g., in full-duplex communications) over the one or multiple BWPs  215 . 
     The UE  115 - a  may be configured to receive a BWP configuration defining a set of resource bandwidths for one or multiple BWPs, such as BWPs  215 . Each resource bandwidth may define time and frequency resources for one or multiple BWPs  215  allocated for duplex communications  210 . The UE  115 - a  may determine that at least one resource bandwidth in the set is an initial resource bandwidth to be used for random access communications in the event that the UE  115 - a  is to transmit a random access request and a current active resource bandwidth at the UE  115 - a  has an absence of configured random access occasions. In other words, the initial resource bandwidth may become an active resource bandwidth for one or more BWPs  215  in the event that an active resource bandwidth does not have a random access occasion. 
       FIG.  3 A  illustrates an example of a wireless communications system  300  that supports bandwidth part and resource bandwidth switching in accordance with aspects of the present disclosure. The wireless communications system  300 - a  may, in some examples, implement aspects of the wireless communications systems  100  or  200 . For example, the wireless communications system  300 - a  may support duplex communications over resource bandwidths in BWPs. In the example of  FIG.  3 A , base stations  105 - b ,  105 - c  may be configured to support full-duplex communications in the wireless communications system  300 - a . For example, the base stations  105 - b ,  105 - c  may support full-duplex communications with UEs  115 - b ,  115 - c . The base stations  105 - b ,  105 - c  and the UEs  115 - b ,  115 - c  may be examples of base stations  105  and UEs  115  described herein. 
     The UEs  115 - b ,  115 - c  may be configured to operate in a half-duplex mode or a full-duplex mode. In the half-duplex mode, the UEs  115 - b ,  115 - c  may be configured to either receive downlink communications from the base stations  105 - b ,  105 - c , or transmit uplink communications to the base stations  105 - b ,  105 - c . In other words, in the half-duplex mode, the UEs  115 - b ,  115 - c  may be unable to jointly receive downlink communications and transmit uplink communications during a same time period using the same frequency resources. In the full-duplex mode, however, the UEs  115 - b ,  115 - c  may be configured to simultaneously receive downlink communications and transmit uplink communications from and to the base stations  105 - b ,  105 - c  during a same time period on a same set of frequency resource. The base station  105 - b ,  105 - c  may provide downlink communications using one or multiple directional beams. Likewise, the UEs  115 - b ,  115 - c  may provide uplink communications using one or multiple directional beams. 
     With reference to  FIG.  3 A , the base stations  105 - b ,  105 - c  may operate in a full-duplex mode, while the UEs  115 - b ,  115 - c  operate in a half-duplex mode. In some cases, one or more of the base stations  105 - b ,  105 - c  and the UEs  115 - b ,  115 - c  may experience interference in the wireless communications system  300 - a . For example, the base station  105 - b  may experience self-interference from downlink communications to uplink communications. By way of example, the base station  105 - b  may transmit downlink communications  305  to the UE  115 - b  using at least one antenna panel of the base station  105 - b , as well as receive uplink communications  310  from the UE  115 - c  using another antenna panel of the base station  105 - b . This may cause self-interference at the base station  105 - b  due to, for example, simultaneous transmission of the downlink communications  305  using the at least one antenna panel of the base station  105 - b  and reception of the uplink communications  310  from the UE  115 - c  using another antenna panel of the base station  105 - b.    
     The base station  105 - b  may experience some interference communications  315  from the base station  105 - c  that may relate to downlink communications from the base station  105 - c  to the UE  115 - b , or downlink communications from the base station  105 - c  to the UE  115 - c . Similarly, the UE  115 - b  may experience some interference communications  315  from the UE  115 - c  that may relate to uplink communications from the UE  115 - c  to the base station  105 - c . Additionally or alternatively, the base station  105 - c  may experience some interference communications  315  from the UE  115 - c  that may relate to the uplink communications  310  from the UE  115 - c  to the base station  105 - b . To mitigate the self-interference at the UEs  115 - b ,  115 - b  (or any other UE  115 ) may use a resource bandwidth of a BWP allocated for uplink communications or downlink communications, or both. 
     For example, the UEs  115 - b ,  115 - c  may be configured to receive a BWP configuration defining a set of resource bandwidths for one or multiple BWPs. Each resource bandwidth may define time and frequency resources for one or multiple BWPs allocated for duplex communications. The UEs  115 - b ,  115 - c  may determine that at least one resource bandwidth in the set is an initial resource bandwidth having one or more random access occasions that are configured. As such, the base stations  105 - b ,  105 - c  may schedule, and the UEs  115 - b ,  115 - c  may perform, duplex communications that take into account BWPs and resource bandwidths for the BWPs as described herein. 
       FIG.  3 B  illustrates an example of a wireless communications system  300 - b  in accordance with aspects of the present disclosure. The wireless communications system  300 - b  may, in some examples, implement aspects of the wireless communications systems  100  or  200 . For example, the wireless communications system  300 - b  may support half-duplex communications or full-duplex communications. In the example of  FIG.  3 B , base stations  105 - b ,  105 - c  may be configured to support full-duplex communications in the wireless communications system  300 - b . For example, the base stations  105 - b ,  105 - c  may support full-duplex communications with UEs  115 - b ,  115 - c . The base stations  105 - b ,  105 - c  and the UEs  115 - b ,  115 - c  may be examples of base stations  105  and UEs  115  described herein. 
     In the example of  FIG.  3 B , the UEs  115 - b ,  115 - c  may be configured to operate in a full-duplex mode. In the full-duplex mode, the UEs  115 - b ,  115 - c  may be configured to concurrently receive downlink communications and transmit uplink communications from and to the base stations  105 - b ,  105 - c . Likewise, the base stations  105 - b ,  105 - c  may also operate in a full-duplex mode. The base station  105 - b ,  105 - c  may provide downlink communications using one or multiple directional beams. Similarly, the UEs  115 - b ,  115 - c  may provide uplink communications using one or multiple directional beams. In some cases, one or more of the base stations  105 - b ,  105 - c  and the UEs  115 - b ,  115 - c  may experience self-interference or other interference in the wireless communications system  300 - b . For example, the UE  115 - b  may experience self-interference from downlink communications to uplink communications. 
     By way of example, the base station  105 - b  may transmit downlink communications  305  to the UE  115 - b , which the UE  115 - b  may receive via at least one antenna panel of the UE  115 - b . The UE  115 - b  may also transmit uplink communications  310  to the base station  105 - b  via another antenna panel of the UE  115 - b . This may cause self-interference at the UE  115 - b  due to, for example, simultaneous reception of the downlink communications  305  using the at least one antenna panel of the UE  115 - b  and transmission of the uplink communications  310  using the other antenna panel of the UE  115 - b . Likewise, the base station  105 - c  may transmit downlink communications  305  to the UE  115 - c , and the UE  115 - c  may transmit uplink communications (not shown) to the base station  105 - c . This may cause self-interference at the UE  115 - c . The base station  105 - b  or the UE  115 - b , or both, may also experience some interference communications  315  from the base station  105 - c  or the UE  115 - c , or both. The interference communications  315  may be associated with the downlink communications  305  from the base station  105 - c  to the UE  115 - c , or the uplink communications (not shown) from the UE  115 - c  to the base station  105 - c , or both. To reduce or eliminate the self-interference at the UEs  115 - b ,  115 - c  (or any other UE  115 ) may communicate using one or more resource bandwidths for a BWP allocated for uplink communications or downlink communications, or both. 
     For example, the UEs  115 - b ,  115 - c  may be configured to receive a BWP configuration defining a set of resource bandwidths for one or multiple BWPs. The UEs  115 - b ,  115 - c  may determine that at least one resource bandwidth in the set is an initial resource bandwidth, as discussed herein. The base stations  105 - b ,  105 - c  may schedule, and the UEs  115 - b ,  115 - c  may perform duplex communications that take into account BWPs and resource bandwidths for the BWPs as described herein. 
       FIG.  3 C  illustrates an example of a wireless communications system  300 - c  in accordance with aspects of the present disclosure. The wireless communications system  300 - c  may, in some examples, implement aspects of the wireless communications systems  100  or  200 . For example, the wireless communications system  300 - c  may support half-duplex communications or full-duplex communications. In the example of  FIG.  3 C , base stations  105 - b ,  105 - c  may be configured to support full-duplex communications in the wireless communications system  300 - b . For example, the base stations  105 - b ,  105 - c  may support full-duplex communications with UEs  115 - b ,  115 - c . The base stations  105 - b ,  105 - c  and the UEs  115 - b ,  115 - c  may be examples of base stations  105  and UEs  115  described herein. 
     In the example of  FIG.  3 C , the UEs  115 - b ,  115 - c  may be configured to operate in a full-duplex mode with multiple-transmission and reception points (multi-TRPs). In the full-duplex mode, the UEs  115 - b ,  115 - c  may be configured to concurrently receive downlink communications and transmit uplink communications from and to the base stations  105 - b ,  105 - c . Likewise, the base stations  105 - b ,  105 - c  may also operate in a full-duplex mode. The base station  105 - b ,  105 - c  may provide downlink communications using one or multiple directional beams. Similarly, the UEs  115 - b ,  115 - c  may provide uplink communications using one or multiple directional beams. In some cases, one or more of the base stations  105 - b ,  105 - c  and the UEs  115 - b ,  115 - c  may experience self-interference or other interference in the wireless communications system  300 - b . For example, the UE  115 - b  may experience self-interference from downlink communications to uplink communications. 
     By way of example, the UE  115 - b  may receive downlink communications  305  from the base station  105 - c  using one TRP of the UE  115 - b , and transmit uplink communications  310  to the base station  105 - b  using another TRP of the UE  115 . The reception of the downlink communications  305  and the transmission of the uplink communications  310  may occur simultaneously. This may cause self-interference at the UE  115 - b . Similarly, the base station  105 - c  may transmit downlink communications  305  to the UE  115 - b  using one TRP of the base station  105 - c  and transmit downlink communications  305  to the UE  115 - c  using another TRP of the base station  105 - c . To reduce or eliminate the self-interference at the UEs  115 - b ,  115 - c  (or any other UE  115 ) one or more resource bandwidths for one or more BWPs may be allocated for uplink communications or downlink communications, or both. 
     The UEs  115 - b ,  115 - c  may be configured to receive a BWP configuration defining a set of resource bandwidths for one or multiple BWPs. The UEs  115 - b ,  115 - c  may determine that at least one resource bandwidth in the set is an initial resource bandwidth, as discussed herein. The base stations  105 - b ,  105 - c  may schedule, and the UEs  115 - b ,  115 - c  may perform duplex communications that take into account BWPs and resource bandwidths for the BWPs as described herein. 
       FIG.  4 A  illustrates an example of a configuration  400 - a  that supports bandwidth part and resource bandwidth switching in accordance with aspects of the present disclosure. The configuration  400 - a  may implement aspects of the wireless communications systems  100  or  200 . For example, the configuration  400 - a  may be based on a full-duplex configuration provided by a base station  105  and implemented by the base station  105  or a UE  115 , or both. In some examples, the base station  105  or the UE  115 , or both, may support in-band full-duplex (IBFD) operations. According to IBFD operations, the base station  105  and the UE  115  may transmit and receive communications simultaneously in a same frequency band, and thereby increase throughput of a wireless communications systems, for example the wireless communications systems  100 ,  200 , or  300 . 
     The base station  105  and the UE  115  may, for example, transmit and receive communications (e.g., downlink communications  405 , uplink communications  410 ) on same time and frequency resources, such as symbol, a minislot, a subframe, frames, subcarriers, carriers, etc. The downlink communications  405  and the uplink communications  410  may thereby share same IBFD time and frequency resources. The base station  105  may provide downlink communications  405  using one or multiple directional beams via one or more antenna panels. Similarly, the UE  115  may provide uplink communications  410  using one or multiple directional beams via one or more antenna panels. In some examples, there may be a full overlap  415  between IBFD time and frequency resources associated with the downlink communications  405  and the uplink communications  410 . In some other examples, there may be a partial overlap  420  between IBFD time and frequency resources associated with the downlink communications  405  and the uplink communications  410 . In accordance with aspects of the present disclosure, a UE  115  operating in a full-duplex mode, such as configurations illustrated by the configuration  400 - a , may determine one or more resource bandwidths for one or more BWPs allocated for uplink communications or downlink communications, or both, where one or more initial resource bandwidths are configured that have one or more random access occasions. 
     For example, a UE  115  may be configured to receive a BWP configuration defining a set of resource bandwidths for one or multiple BWPs. The UE  115  may determine that at least one resource bandwidth in the set is an initial resource bandwidth to be used for random access request transmissions in the event that an active resource bandwidth is not configured with any random access occasions. The base station  105  may schedule, and the UE  115  may perform duplex communications that take into account BWPs and resource bandwidths for the BWPs as described herein. 
       FIG.  4 B  illustrates an example of a configuration  400 - b  that supports bandwidth part and resource bandwidth switching in accordance with aspects of the present disclosure. The configuration  400 - b  may implement aspects of the wireless communications systems  100 ,  200 , or  300 . For example, the configuration  400 - b  may be based on a full-duplex configuration provided by a base station  105 , and implemented by the base station  105  or a UE  115 , or both. The base station  105  may support full-duplex communications including transmitting downlink communications  405 , and receiving uplink communications  410 , using one or multiple directional beams. Similarly, the UE  115  may support full-duplex communications including transmitting uplink communications  410  in an uplink band, and receiving the downlink communications  405  in a downlink band, using one or multiple directional beams via one or more antenna panels. In some examples, the base station  105  or the UE  115 , or both, may support FDD operations resources associated with full-duplex communications. 
     The base station  105  and the UE  115  may, for example, transmit and receive communications (e.g., the downlink communications  405 , the uplink communications  410 ) on same time resources (e.g., symbol, a minislot, a subframe, frames) but different frequency resources (e.g., subcarriers, carriers). As such, the downlink communications  405  and the uplink communications  410  may be separated in a frequency domain. Additionally, or alternatively, there may be a guard band  425  in a frequency domain between the downlink communications  405  in a downlink band and the uplink communications  410  in an uplink band. The guard band  425  may be an unused part of a radio frequency spectrum between at least two radio frequency spectrum subbands or bands, for reducing interference, for example, between the downlink communications  405  in the downlink band and the uplink communications  410  in the uplink band. In accordance with aspects of the present disclosure, a UE  115  operating in a full-duplex mode, such as configurations illustrated by the configuration  400 - b , may determine an initial resource bandwidth for a BWP allocated for uplink communications or downlink communications, or both. 
     For example, a UE  115  may be configured to receive a BWP configuration defining a set of resource bandwidths for one or multiple BWPs. The UE  115  may determine that at least one resource bandwidth in the set is an initial resource bandwidth, as discussed herein. In some examples, the initial resource bandwidth for the UE  115 , for example, may be used if the UE  115  does not determine or has not received any indication about which resource bandwidth to use for one or more given BWPs, or in the event that a MAC entity at the UE  115  determines that a random access request is to be transmitted and a current active resource bandwidth has an absence of configured random access occasions. The base station  105  may schedule, and the UE  115  may perform duplex communications that take into account BWPs and resource bandwidths for the BWPs as described herein. 
       FIG.  5    illustrates an example of a radio frequency spectrum subband configuration  500  that supports bandwidth part and resource bandwidth switching in accordance with aspects of the present disclosure. The radio frequency spectrum subband configuration  500  may implement aspects of the wireless communications systems  100 ,  200 , or  300 . For example, a base station  105  or a UE  115 , or both, as described herein may support various types of frequency ranges, such as Sub 6 GHz range (also referred to as FR1) and millimeter wave (mmW) range (also referred to as FR2 or FR4). In some examples, the base station  105  or the UE  115 , or both, may support a multiplexing operation on time and frequency resources when operating in one or multiple radio frequency spectrum subbands. The multiplexing operation may be an FDD operation and a TDD operation. The radio frequency spectrum subband configuration  500  may reduce or mitigate self-interference by isolating antenna panels of the base station  105  or the UE  115 , or both. This isolation may provide an improvement to reduction of noise experienced at antenna panels (e.g., signal-to-noise ratio (SNR)&gt;50 db or SNR&gt;40 dB for sub-band full duplex). 
     In the example of  FIG.  5   , the base station  105  or the UE  115 , or both, may support an FDD operation and a TDD operation on time and frequency resources for downlink communications (e.g., downlink control  505 , downlink data  510 ) and uplink communications (e.g., uplink control  515 , uplink data  520 ) in an unpaired spectrum. One or more downlink bands and one or more uplink bands may be in different portions of a radio frequency spectrum. In some examples, there may be a guard band between a downlink band and an uplink band. The base station  105  may provide downlink communications (e.g., downlink control  505 , downlink data  510 ) using one or multiple directional beams via one or multiple antenna panels according to the radio frequency spectrum subband configuration  500  (e.g., TDD and FDD). The UE  115  may also provide uplink communications (e.g., uplink control  515 , uplink data  520 ) using one or multiple directional beams via one or multiple antenna panels according to the radio frequency spectrum subband configuration  500  (e.g., TDD and FDD). The base station  105  or the UE  115 , or both, may thus support FDD and TDD operations in an unpaired spectrum for duplexed communications between the base station  105  and the UE  115 . 
     The radio frequency spectrum subband configuration  500  may mitigate self-interference at a base station  105  or a UE  115 , or both. For example, the base station  105  or the UE  115 , or both, may be configured with at least two separate antenna panels for simultaneous transmission and reception operations. For example, the base station  105  may be configured with at least two separate antenna panels for simultaneous transmission and reception operations. Likewise, the UE  115  may be configured with at least two separate antenna panels for simultaneous transmission and reception operations. With reference to  FIG.  5   , in some examples, one antenna panel of the two may be configured for downlink transmission at both edges of the radio frequency spectrum subband configuration  500 , while the other antenna panel of the two may be configured for uplink reception in the middle of the radio frequency spectrum subband configuration  500 . 
     The base station  105  or the UE  115 , or both, may support a time domain windowed overlap-and-add (WOLA) to reduce an adjacent-channel-leakage-ratio (ACLR) for a downlink signal or an uplink signal. The base station  105  or the UE  115 , or both, may use an analog low-pass filter to improve an analog-to-digital converter (ADC) dynamic range. The base station  105  or the UE  115 , or both, may improve automatic gain control (AGC) states to improve a noise figure (NF). In some examples, a digital integrated circuit (IC) of the ACLR leakage may be above 20 dB (i.e., ACLR leakage&gt;20 db). The base station  105  or the UE  115 , or both, may use a non-linear model per each transmitter-receiver pair. In accordance with aspects of the present disclosure, a UE  115  operating in a full-duplex mode, such as configurations illustrated by the radio frequency spectrum subband configuration  500 , may determine an initial resource bandwidth for a BWP allocated for uplink communications or downlink communications, or both. As such, a base station  105  may schedule, and the UE  115  may perform, duplex communications that take into account BWPs and resource bandwidths for the BWPs as described herein. 
     Returning to  FIG.  2   , the UE  115 - a  may switch a BWP when communicating with the base station  105 - a . For example, the UE  115 - a  may switch from a BWP  220  to a BWP  225  for communicating with the base station  105 - a . In some examples, the UE  115 - a  may switch a BWP based on receiving a message from the base station  105 - a . In some examples, the message may be a DCI message that may include a DCI command for the UE  115 - a  to switch a BWP and include a BWP identifier that may indicate for the UE  115 - a  the BWP to switch to. The message may identify a specific BWP that can be activated by a BWP identifier (e.g., which may also be referred to as a BWP indicator). In some other examples, the message may be an RRC message or a MAC-CE, among others. 
     A bandwidth within a BWP (e.g., the BWP  220  or the BWP  225 , or both) may, in some cases, be impacted because of a downlink band, a guard band, or an uplink band, or any combination thereof. The base station  105 - a  may thus configure the UE  115 - a  with one or more resource bandwidths that correspond to time and frequency resources associated with the BWP allocated for downlink communications or uplink communications. The resource bandwidths may thus accommodate disjoint bandwidth allocation for duplex communications, such as full-duplex communications supporting both downlink communications and uplink communications. In some cases, the base station  105 - a  and the UE  115 - a  may support joint indication to switch BWP and resource bandwidths. 
     The UE  115 - a  may be configured to receive, from the base station  105 - a , a BWP configuration defining a set of resource bandwidths for one or multiple BWPs  215 . Each resource bandwidth may define time and frequency resources for one or multiple BWPs  215  allocated for downlink communications or uplink communications. The UE  115 - a  may determine that at least one resource bandwidth in the set is an initial resource bandwidth used for uplink communications of random access requests, in the event that a currently active resource bandwidth is not configured with a random access occasion. 
       FIG.  6    illustrates an example of a BWP configuration  600  that supports bandwidth part and resource bandwidth switching in accordance with aspects of the present disclosure. The BWP configuration  600  may implement aspects of the wireless communications systems  100 ,  200 , or  300  described with reference to  FIGS.  1 - 3   , respectively. For example, the BWP configuration  600  may support half-duplex communications or full-duplex communications. The BWP configuration  600  may be based on a configuration by a base station  105  or a UE  115 , and implemented by the UE  115  and may promote fast switching in duplex communications by supporting resource bandwidth and BWP operations. The BWP configuration  600  may also be based on a configuration by the base station  105  or the UE  115 , and implemented by the UE  115  to promote high reliability and low latency wireless communications by providing an indication identifying one or more BWPs and one or more resource bandwidths, among other benefits. 
     A UE  115  may communicate (e.g., receive downlink communications or transmit uplink communications or both) with a base station  105 , or another UE  115 , or both, over one or more BWPs. For example, an uplink BWP  605  may be configured for uplink communications of the UE  115  and the base station  105 , and a downlink BWP  610  may be configured for downlink communications of the UE  115  and base station  105 . As shown, resource bandwidths  615 ,  620 ,  625 , and  630  are associated with the uplink BWP  605 , while resource bandwidths  640 ,  645 ,  650 , and  655  are associated with the uplink BWP  610 , In some cases, the UE  115  may identify a set of resource bandwidths (e.g., time and frequency resources) of the uplink BWP  605  and the downlink BWP  610 , or both, based on a BWP configuration received from the base station  105  (e.g., via RRC signaling). For example, for the uplink BWP  605 , the UE  115  may identify, based on the BWP configuration, a resource bandwidth  615 , or a resource bandwidth  620 , or a resource bandwidth  625 , or a resource bandwidth  630 , or any combination thereof. Additionally, or alternatively, the UE  115  may identify, based on the BWP configuration, a resource bandwidth  640 , or a resource bandwidth  645 , or a resource bandwidth  650 , or a resource bandwidth  655 , or any combination thereof. In some examples, the UE  115  may receive separate BWP configurations for the uplink BWP  605  and the downlink BWP  610 , or the BWP configurations may be configured such that corresponding resource bandwidths within each BWP  605 ,  610 , have corresponding resource bandwidth identification and occupy the same resources in relation to BWP boundaries. 
     The UE  115  may determine that at least one resource bandwidth of the set of resource bandwidths is an initial resource bandwidth  635  for the uplink BWP  605 . In some examples, the UE  115  may receive an indication of the initial resource bandwidth  635  from the base station  105 . The UE  115  may determine that the at least one resource bandwidth of the set of resource bandwidths is the initial resource bandwidth based on the indication. In other cases, the initial resource bandwidth  635  may be determined based on a defined resource bandwidth ID. In some examples, the UE  115  may receive an RRC message including the indication of the initial resource bandwidth  635 . In some other examples, the UE  115  may receive a DCI message or a MAC-CE including the indication of the initial resource bandwidth. 
     Each resource bandwidth may span an entire BWP  605 ,  610 , or a portion of a BWP  605 ,  610 . Further, a resource bandwidth may be non-contiguous in the frequency domain within a configured BWP  605 ,  610 , such as illustrated for resource bandwidth  625  and resource bandwidth  655 . Additionally, or alternatively, the uplink BWP  605  may be identified as an initial uplink BWP, and multiple uplink BWPs may be configured. In some examples, the initial resource bandwidth  635  is used for uplink communications, for example, if the UE  115  does not determine or has not received any indication about which resource bandwidth to use for the uplink BWP (e.g., if a BWP or resource bandwidth has not been activated at the UE  115 ). In other words, the initial resource bandwidth may become an active resource bandwidth for a BWP unless the UE is signaled a particular resource bandwidth to use for the BWP (e.g., signaled by a base station). Therefore, the UE may communicate with a base station using the initial resource bandwidth or a particular active resource bandwidth signaled to the UE. 
     As discussed herein, the UE  115  may be configured with one or more random access occasions  660 , which may be used to transmit a random access request to the base station as part of a random access procedure. In some cases, a portion (e.g., only a portion) of the configured BWPs  605 ,  610 , a portion of the resource bandwidths, or combinations thereof, may be configured with random access occasions  660 . In some cases, the initial uplink BWP  605  and one or more initial resource bandwidths  635  (e.g., one initial resource bandwidth for each configured uplink BWP), may be configured with random access occasions  660 , such that the UE  115  may be able to transmit a random access request in the event that no active uplink BWP or resource bandwidth is present and configured with a random access occasion  660 . In some cases, the initial resource bandwidth  635  is configured in radio resource control (RRC) signaling from the base station. Thus, in the event that a MAC entity at the UE  115  determines that a random access request is to be transmitted, the MAC entity may switch the resource bandwidth and/or the uplink BWP to the initial resource bandwidth  635  of the uplink BWP  605 , in the event that the active resource bandwidth and/or BWP do not have any configured random access occasions  660 . 
     In some cases, the initial resource bandwidth  635  may have a defined resource bandwidth identification (e.g., a resource bandwidth ID of 0 or 1), and any configured resource bandwidth having the defined resource bandwidth identification may be considered to be an initial resource bandwidth  635 . The random access occasions  660  in such cases are configured in uplink resource bandwidths, which may be configured separately from downlink BWP  610  and downlink resource bandwidths. In some cases, the corresponding resource bandwidth in the downlink BWP  610  has the same resource bandwidth identification as the initial resource bandwidth  635  in the corresponding uplink BWP  605 . The initial resource bandwidth may span the entire bandwidth of the associated BWP  605 , may span a portion of the bandwidth of the BWP  605 , and can include disjoint or include non-contiguous frequency-domain resources. In some cases, resource bandwidths may include one or more resource bandwidths that are designed for half-duplex mode operations at the UE. In some cases, an uplink BWP configured with multiple resource bandwidths might have none of the resource bandwidth is initial resource bandwidth (i.e., the initial resource bandwidth is not configured), an initial resource bandwidth that is configured, or multiple resource bandwidths that are configured with random access occasions  660 . 
     In some cases, if the MAC entity initiates a random access procedure, it may be determined whether a currently active resource bandwidth is configured with random access occasions  660  (e.g., if resource bandwidth  625  is currently active). If the currently active resource bandwidth does have one or more random access occasions  660  configured, the UE  115  does not switch the resource bandwidth or the BWP, and a random access request may be transmitted in one of the configured random access occasions  660  of the active resource bandwidth. If the active resource bandwidth of the UE  115  is not configured with any random access occasions (e.g., if resource bandwidth  620  or  630  is an active resource bandwidth), the MAC entity at the UE  115  may switch the resource bandwidth to the initial resource bandwidth  635 . In cases where the active resource bandwidth is not configured with random access occasions  660  and the initial resource bandwidth is not configured in the active BWP, or if the initial resource bandwidth of the active BWP is configured without random access occasions, the UE  115  may switch the active BWP to the initial uplink BWP  605 , and the initial resource bandwidth  635  is selected from the initial uplink BWP  605 . The initial resource bandwidth  635  in the initial uplink BWP  605  will become the active resource bandwidth. 
     For downlink communications, the UE  115  may or may not switch the active resource bandwidth, based on which downlink BWP  610  and downlink resource bandwidth is active at the UE. For example, if the active resource bandwidth includes random access monitoring resources  665  as part of a random access configuration, the UE  115  will not switch the active resource bandwidth or BWP. If the UE  115  switches the active downlink resource bandwidth, it may be switched to the resource bandwidth with a resource bandwidth identification that corresponds to the initial resource bandwidth identification, which the base station  105  may use to transmit the random access response. 
       FIG.  7    shows a block diagram  700  of a device  705  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The device  705  may be an example of aspects of a UE  115  as described herein. The device  705  may include a receiver  710 , a communications manager  715 , and a transmitter  720 . The device  705  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  710  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to bandwidth part and resource bandwidth switching in wireless communications, etc.). Information may be passed on to other components of the device  705 . The receiver  710  may be an example of aspects of the transceiver  1020  described with reference to  FIG.  10   . The receiver  710  may utilize a single antenna or a set of antennas. 
     The communications manager  715  may receive, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, determine to transmit a random access request to the base station and that an active resource bandwidth for communications with the base station has an absence of random access occasions, transmit the random access request in the selected first random access occasion, and select, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth. The communications manager  715  may be an example of aspects of the communications manager  1010  described herein. 
     The communications manager  715 , or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager  715 , or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. 
     The communications manager  715 , or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager  715 , or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager  715 , or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. 
     The transmitter  720  may transmit signals generated by other components of the device  705 . In some examples, the transmitter  720  may be collocated with a receiver  710  in a transceiver module. For example, the transmitter  720  may be an example of aspects of the transceiver  1020  described with reference to  FIG.  10   . The transmitter  720  may utilize a single antenna or a set of antennas. 
       FIG.  8    shows a block diagram  800  of a device  805  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The device  805  may be an example of aspects of a device  705 , or a UE  115  as described herein. The device  805  may include a receiver  810 , a communications manager  815 , and a transmitter  835 . The device  805  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  810  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to bandwidth part and resource bandwidth switching in wireless communications, etc.). Information may be passed on to other components of the device  805 . The receiver  810  may be an example of aspects of the transceiver  1020  described with reference to  FIG.  10   . The receiver  810  may utilize a single antenna or a set of antennas. 
     The communications manager  815  may be an example of aspects of the communications manager  715  as described herein. The communications manager  815  may include a configuration manager  820 , a random access manager  825 , and a resource selection manager  830 . The communications manager  815  may be an example of aspects of the communications manager  1010  described herein. 
     The configuration manager  820  may receive, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions. 
     The random access manager  825  may determine to transmit a random access request to the base station and that an active resource bandwidth for communications with the base station has an absence of random access occasions and transmit the random access request in the selected first random access occasion. 
     The resource selection manager  830  may select, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth. 
     The transmitter  835  may transmit signals generated by other components of the device  805 . In some examples, the transmitter  835  may be collocated with a receiver  810  in a transceiver module. For example, the transmitter  835  may be an example of aspects of the transceiver  1020  described with reference to  FIG.  10   . The transmitter  835  may utilize a single antenna or a set of antennas. 
       FIG.  9    shows a block diagram  900  of a communications manager  905  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The communications manager  905  may be an example of aspects of a communications manager  715 , a communications manager  815 , or a communications manager  1010  described herein. The communications manager  905  may include a configuration manager  910 , a random access manager  915 , a resource selection manager  920 , a RRC manager  925 , a MAC entity  930 , and a switching manager  935 . Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses). 
     The configuration manager  910  may receive, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions. In some cases, the two or more bandwidth parts are configured for full-duplex communications between the UE and the base station, and where the initial resource bandwidth spans a portion of an associated bandwidth part of the two or more bandwidth parts that is compatible with half-duplex communications. In some cases, the initial resource bandwidth is configured within one or more uplink bandwidth parts of the two or more bandwidth parts. In some cases, the initial resource bandwidth has a bandwidth identification within a corresponding uplink bandwidth part of the one or more uplink bandwidth parts, and where a corresponding downlink resource bandwidth has a corresponding downlink resource bandwidth identification within a downlink bandwidth part. In some cases, the initial resource bandwidth spans contiguous or disjoint frequency domain resources of the associated bandwidth part. In some cases, a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths, none of which are configured as the initial resource bandwidth. In some cases, a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths that are configured with one or more random access occasions. 
     The random access manager  915  may determine to transmit a random access request to the base station and that an active resource bandwidth for communications with the base station has an absence of random access occasions. In some examples, the random access manager  915  may transmit the random access request in the selected first random access occasion. 
     The resource selection manager  920  may select, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth. In some examples, the resource selection manager  920  may determine to transmit the random access request using the active resource bandwidth when the active resource bandwidth has one or more random access occasions. In some cases, the initial resource bandwidth spans entire frequency domain bandwidth of the associated bandwidth part. 
     The RRC manager  925  may receive RRC signaling that configures the two or more bandwidth parts, the two or more resource bandwidths, and one or more initial resource bandwidths within one or more of the bandwidth parts. The MAC entity  930  may determine to transmit the random access request for communications with the base station. 
     The switching manager  935  may switch the active resource bandwidth from a first uplink resource bandwidth to the initial resource bandwidth based on the first uplink resource bandwidth having an absence of random access occasions. In some examples, the switching manager  935  may switch a downlink resource bandwidth to correspond with the initial resource bandwidth. In some examples, the switching manager  935  may determine that the active resource bandwidth within an active uplink bandwidth part is not configured with a random access occasion, and that an initial resource bandwidth of the active uplink bandwidth part is not configured or is configured without a random access occasion. In some examples, the switching manager  935  may switch the active uplink bandwidth part to an initial uplink bandwidth part that is configured with the initial resource bandwidth that includes the first random access occasion. In some cases, an active downlink bandwidth part corresponds to the initial uplink bandwidth part, and an active downlink resource bandwidth corresponds to the initial resource bandwidth, subsequent to the switching. 
       FIG.  10    shows a diagram of a system  1000  including a device  1005  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The device  1005  may be an example of or include the components of device  705 , device  805 , or a UE  115  as described herein. The device  1005  may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager  1010 , an I/O controller  1015 , a transceiver  1020 , an antenna  1025 , memory  1030 , and a processor  1040 . These components may be in electronic communication via one or more buses (e.g., bus  1045 ). 
     The communications manager  1010  may receive, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, determine to transmit a random access request to the base station and that an active resource bandwidth for communications with the base station has an absence of random access occasions, transmit the random access request in the selected first random access occasion, and select, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth. 
     The I/O controller  1015  may manage input and output signals for the device  1005 . The I/O controller  1015  may also manage peripherals not integrated into the device  1005 . In some cases, the I/O controller  1015  may represent a physical connection or port to an external peripheral. In some cases, the I/O controller  1015  may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In other cases, the I/O controller  1015  may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller  1015  may be implemented as part of a processor. In some cases, a user may interact with the device  1005  via the I/O controller  1015  or via hardware components controlled by the I/O controller  1015 . 
     The transceiver  1020  may communicate bi-directionally, via one or more antennas, wired, or wireless links as described herein. For example, the transceiver  1020  may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver  1020  may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. 
     In some cases, the wireless device may include a single antenna  1025 . However, in some cases the device may have more than one antenna  1025 , which may be capable of concurrently transmitting or receiving multiple wireless transmissions. 
     The memory  1030  may include RAM and ROM. The memory  1030  may store computer-readable, computer-executable code  1035  including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory  1030  may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. 
     The processor  1040  may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor  1040  may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor  1040 . The processor  1040  may be configured to execute computer-readable instructions stored in a memory (e.g., the memory  1030 ) to cause the device  1005  to perform various functions (e.g., functions or tasks supporting bandwidth part and resource bandwidth switching in wireless communications). 
     The code  1035  may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code  1035  may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code  1035  may not be directly executable by the processor  1040  but may cause a computer (e.g., when compiled and executed) to perform functions described herein. 
       FIG.  11    shows a block diagram  1100  of a device  1105  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The device  1105  may be an example of aspects of a base station  105  as described herein. The device  1105  may include a receiver  1110 , a communications manager  1115 , and a transmitter  1120 . The device  1105  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  1110  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to bandwidth part and resource bandwidth switching in wireless communications, etc.). Information may be passed on to other components of the device  1105 . The receiver  1110  may be an example of aspects of the transceiver  1420  described with reference to  FIG.  14   . The receiver  1110  may utilize a single antenna or a set of antennas. 
     The communications manager  1115  may transmit, to a UE, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, configure the UE with an active resource bandwidth for communications with the base station that has an absence of random access occasions, and monitor the one or more random access occasions of the initial resource bandwidth for a random access request from the UE. The communications manager  1115  may be an example of aspects of the communications manager  1410  described herein. 
     The communications manager  1115 , or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager  1115 , or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. 
     The communications manager  1115 , or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager  1115 , or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager  1115 , or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. 
     The transmitter  1120  may transmit signals generated by other components of the device  1105 . In some examples, the transmitter  1120  may be collocated with a receiver  1110  in a transceiver module. For example, the transmitter  1120  may be an example of aspects of the transceiver  1420  described with reference to  FIG.  14   . The transmitter  1120  may utilize a single antenna or a set of antennas. 
       FIG.  12    shows a block diagram  1200  of a device  1205  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The device  1205  may be an example of aspects of a device  1105 , or a base station  105  as described herein. The device  1205  may include a receiver  1210 , a communications manager  1215 , and a transmitter  1235 . The device  1205  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  1210  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to bandwidth part and resource bandwidth switching in wireless communications, etc.). Information may be passed on to other components of the device  1205 . The receiver  1210  may be an example of aspects of the transceiver  1420  described with reference to  FIG.  14   . The receiver  1210  may utilize a single antenna or a set of antennas. 
     The communications manager  1215  may be an example of aspects of the communications manager  1115  as described herein. The communications manager  1215  may include a configuration manager  1220 , a resource bandwidth manager  1225 , and a random access manager  1230 . The communications manager  1215  may be an example of aspects of the communications manager  1410  described herein. 
     The configuration manager  1220  may transmit, to a UE, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions. 
     The resource bandwidth manager  1225  may configure the UE with an active resource bandwidth for communications with the base station that has an absence of random access occasions. 
     The random access manager  1230  may monitor the one or more random access occasions of the initial resource bandwidth for a random access request from the UE. 
     The transmitter  1235  may transmit signals generated by other components of the device  1205 . In some examples, the transmitter  1235  may be collocated with a receiver  1210  in a transceiver module. For example, the transmitter  1235  may be an example of aspects of the transceiver  1420  described with reference to  FIG.  14   . The transmitter  1235  may utilize a single antenna or a set of antennas. 
       FIG.  13    shows a block diagram  1300  of a communications manager  1305  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The communications manager  1305  may be an example of aspects of a communications manager  1115 , a communications manager  1215 , or a communications manager  1410  described herein. The communications manager  1305  may include a configuration manager  1310 , a resource bandwidth manager  1315 , a random access manager  1320 , and a RRC manager  1325 . Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses). 
     The configuration manager  1310  may transmit, to a UE, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions. In some cases, the initial resource bandwidth spans entire frequency domain bandwidth of the associated bandwidth part. In some cases, the two or more bandwidth parts are configured for full-duplex communications between the UE and the base station, and where the initial resource bandwidth spans a portion of an associated bandwidth part of the two or more bandwidth parts that is compatible with half-duplex communications. In some cases, the initial resource bandwidth is configured within one or more uplink bandwidth parts of the two or more bandwidth parts. In some cases, the initial resource bandwidth has a bandwidth identification within a corresponding uplink bandwidth part of the one or more uplink bandwidth parts, and where a corresponding downlink resource bandwidth has a corresponding downlink resource bandwidth identification within a downlink bandwidth part. In some cases, the random access request is transmitting by the UE using the active resource bandwidth when the active resource bandwidth has one or more random access occasions. In some cases, the UE switches the active resource bandwidth from a first uplink resource bandwidth to the initial resource bandwidth based on the first uplink resource bandwidth having an absence of random access occasions. In some cases, a downlink resource bandwidth for a random access response transmission corresponds with the initial resource bandwidth. 
     The resource bandwidth manager  1315  may configure the UE with an active resource bandwidth for communications with the base station that has an absence of random access occasions. In some cases, the initial resource bandwidth spans contiguous or disjoint frequency domain resources of the associated bandwidth part. In some cases, a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths, none of which are configured as the initial resource bandwidth. In some cases, a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths that are configured with one or more random access occasions. 
     The random access manager  1320  may monitor the one or more random access occasions of the initial resource bandwidth for a random access request from the UE. In some cases, the initial resource bandwidth is in an initial bandwidth part that is configured with random access occasions, and where the active resource bandwidth of the UE is not configured with a random access occasion, and an active uplink bandwidth part of the UE is not configured with an initial resource bandwidth with a random access occasion. In some cases, an active downlink bandwidth part corresponds to the initial uplink bandwidth part, and an active downlink resource bandwidth corresponds to the initial resource bandwidth, subsequent to the switching. 
     The RRC manager  1325  may transmit RRC signaling that configures the two or more bandwidth parts, the two or more resource bandwidths, and one or more initial resource bandwidths within one or more of the bandwidth parts. 
       FIG.  14    shows a diagram of a system  1400  including a device  1405  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The device  1405  may be an example of or include the components of device  1105 , device  1205 , or a base station  105  as described herein. The device  1405  may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager  1410 , a network communications manager  1415 , a transceiver  1420 , an antenna  1425 , memory  1430 , a processor  1440 , and an inter-station communications manager  1445 . These components may be in electronic communication via one or more buses (e.g., bus  1450 ). 
     The communications manager  1410  may transmit, to a UE, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions, configure the UE with an active resource bandwidth for communications with the base station that has an absence of random access occasions, and monitor the one or more random access occasions of the initial resource bandwidth for a random access request from the UE. 
     The network communications manager  1415  may manage communications with the core network (e.g., via one or more wired backhaul links). For example, the network communications manager  1415  may manage the transfer of data communications for client devices, such as one or more UEs  115 . 
     The transceiver  1420  may communicate bi-directionally, via one or more antennas, wired, or wireless links as described herein. For example, the transceiver  1420  may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver  1420  may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. 
     In some cases, the wireless device may include a single antenna  1425 . However, in some cases the device may have more than one antenna  1425 , which may be capable of concurrently transmitting or receiving multiple wireless transmissions. 
     The memory  1430  may include RAM, ROM, or a combination thereof. The memory  1430  may store computer-readable code  1435  including instructions that, when executed by a processor (e.g., the processor  1440 ) cause the device to perform various functions described herein. In some cases, the memory  1430  may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. 
     The processor  1440  may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor  1440  may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor  1440 . The processor  1440  may be configured to execute computer-readable instructions stored in a memory (e.g., the memory  1430 ) to cause the device  1405  to perform various functions (e.g., functions or tasks supporting bandwidth part and resource bandwidth switching in wireless communications). 
     The inter-station communications manager  1445  may manage communications with other base station  105 , and may include a controller or scheduler for controlling communications with UEs  115  in cooperation with other base stations  105 . For example, the inter-station communications manager  1445  may coordinate scheduling for transmissions to UEs  115  for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager  1445  may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations  105 . 
     The code  1435  may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code  1435  may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code  1435  may not be directly executable by the processor  1440  but may cause a computer (e.g., when compiled and executed) to perform functions described herein. 
       FIG.  15    shows a flowchart illustrating a method  1500  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The operations of method  1500  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1500  may be performed by a communications manager as described with reference to  FIGS.  7  through  10   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, a UE may perform aspects of the functions described herein using special-purpose hardware. 
     At  1505 , the UE may receive, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions. The operations of  1505  may be performed according to the methods described herein. In some examples, aspects of the operations of  1505  may be performed by a configuration manager as described with reference to  FIGS.  7  through  10   . 
     At  1510 , the UE may determine to transmit a random access request to the base station and that an active resource bandwidth for communications with the base station has an absence of random access occasions. The operations of  1510  may be performed according to the methods described herein. In some examples, aspects of the operations of  1510  may be performed by a random access manager as described with reference to  FIGS.  7  through  10   . 
     At  1515 , the UE may select, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth. The operations of  1515  may be performed according to the methods described herein. In some examples, aspects of the operations of  1515  may be performed by a resource selection manager as described with reference to  FIGS.  7  through  10   . 
     At  1520 , the UE may transmit the random access request in the selected first random access occasion. The operations of  1520  may be performed according to the methods described herein. In some examples, aspects of the operations of  1520  may be performed by a random access manager as described with reference to  FIGS.  7  through  10   . 
       FIG.  16    shows a flowchart illustrating a method  1600  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The operations of method  1600  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1600  may be performed by a communications manager as described with reference to  FIGS.  7  through  10   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, a UE may perform aspects of the functions described herein using special-purpose hardware. 
     At  1605 , the UE may receive, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions. The operations of  1605  may be performed according to the methods described herein. In some examples, aspects of the operations of  1605  may be performed by a configuration manager as described with reference to  FIGS.  7  through  10   . 
     At  1610 , the UE may determine, by a medium access control (MAC) entity at the UE, to transmit the random access request for communications with the base station. The operations of  1610  may be performed according to the methods described herein. In some examples, aspects of the operations of  1610  may be performed by a MAC entity as described with reference to  FIGS.  7  through  10   . In cases where the active resource bandwidth has one or more random access occasions the UE may determine to transmit the random access request using the active resource bandwidth. In other cases, such as illustrated in this example, the active resource bandwidth may not have any configured random access occasions. 
     At  1615 , the UE may determine to transmit a random access request to the base station and that an active resource bandwidth for communications with the base station has an absence of random access occasions. The operations of  1615  may be performed according to the methods described herein. In some examples, aspects of the operations of  1615  may be performed by a random access manager as described with reference to  FIGS.  7  through  10   . 
     At  1620 , the UE may select, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth. The operations of  1620  may be performed according to the methods described herein. In some examples, aspects of the operations of  1620  may be performed by a resource selection manager as described with reference to  FIGS.  7  through  10   . 
     At  1625 , the UE may switch the active resource bandwidth to the initial resource bandwidth based on the active uplink resource bandwidth having an absence of random access occasions. The operations of  1625  may be performed according to the methods described herein. In some examples, aspects of the operations of  1625  may be performed by a switching manager as described with reference to  FIGS.  7  through  10   . 
     Optionally, at  1630 , the UE may switch a downlink resource bandwidth to correspond with the initial resource bandwidth. The operations of  1630  may be performed according to the methods described herein. In some examples, aspects of the operations of  1630  may be performed by a switching manager as described with reference to  FIGS.  7  through  10   . In some cases, the downlink resource bandwidth may already be the active resource bandwidth, and in such cases the UE may not need to switch the downlink resource bandwidth. In other cases, the downlink resource bandwidth may have a same resource bandwidth ID at the active uplink resource bandwidth, and may thus be switched to a resource bandwidth ID that corresponds to the initial resource bandwidth in order to monitor for a random access response from the base station. 
     At  1635 , the UE may transmit the random access request in the selected first random access occasion. The operations of  1635  may be performed according to the methods described herein. In some examples, aspects of the operations of  1635  may be performed by a random access manager as described with reference to  FIGS.  7  through  10   . 
       FIG.  17    shows a flowchart illustrating a method  1700  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The operations of method  1700  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1700  may be performed by a communications manager as described with reference to  FIGS.  7  through  10   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, a UE may perform aspects of the functions described herein using special-purpose hardware. 
     At  1705 , the UE may receive, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions. The operations of  1705  may be performed according to the methods described herein. In some examples, aspects of the operations of  1705  may be performed by a configuration manager as described with reference to  FIGS.  7  through  10   . 
     At  1710 , the UE may determine that the active resource bandwidth within an active uplink bandwidth part is not configured with a random access occasion, and that an initial resource bandwidth of the active uplink bandwidth part is not configured or is configured without a random access occasion. The operations of  1710  may be performed according to the methods described herein. In some examples, aspects of the operations of  1710  may be performed by a switching manager as described with reference to  FIGS.  7  through  10   . 
     At  1715 , the UE may select, responsive to the determining, a first random access occasion from the one or more random access occasions of the initial resource bandwidth. The operations of  1715  may be performed according to the methods described herein. In some examples, aspects of the operations of  1715  may be performed by a resource selection manager as described with reference to  FIGS.  7  through  10   . 
     At  1720 , the UE may switch the active uplink bandwidth part to an initial uplink bandwidth part that is configured with the initial resource bandwidth that includes the first random access occasion. The operations of  1720  may be performed according to the methods described herein. In some examples, aspects of the operations of  1720  may be performed by a switching manager as described with reference to  FIGS.  7  through  10   . 
     At  1725 , the UE may transmit the random access request in the selected first random access occasion. The operations of  1725  may be performed according to the methods described herein. In some examples, aspects of the operations of  1725  may be performed by a random access manager as described with reference to  FIGS.  7  through  10   . 
       FIG.  18    shows a flowchart illustrating a method  1800  that supports bandwidth part and resource bandwidth switching in wireless communications in accordance with aspects of the present disclosure. The operations of method  1800  may be implemented by a base station  105  or its components as described herein. For example, the operations of method  1800  may be performed by a communications manager as described with reference to  FIGS.  11  through  14   . In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described herein. Additionally or alternatively, a base station may perform aspects of the functions described herein using special-purpose hardware. 
     At  1805 , the base station may transmit, to a UE, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions. The operations of  1805  may be performed according to the methods described herein. In some examples, aspects of the operations of  1805  may be performed by a configuration manager as described with reference to  FIGS.  11  through  14   . 
     At  1810 , the base station may configure the UE with an active resource bandwidth for communications with the base station that has an absence of random access occasions. The operations of  1810  may be performed according to the methods described herein. In some examples, aspects of the operations of  1810  may be performed by a resource bandwidth manager as described with reference to  FIGS.  11  through  14   . 
     At  1815 , the base station may monitor the one or more random access occasions of the initial resource bandwidth for a random access request from the UE. The operations of  1815  may be performed according to the methods described herein. In some examples, aspects of the operations of  1815  may be performed by a random access manager as described with reference to  FIGS.  11  through  14   . 
     It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined. 
     Aspect 1: A method for wireless communication at a UE, comprising: receiving, from a base station, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions; selecting a first random access occasion from the one or more random access occasions of the initial resource bandwidth based at least in part on an active resource bandwidth for communications with the base station having an absence of random access occasions; and transmitting, to the base station, the random access request in the selected first random access occasion. 
     Aspect 2: The method of aspect 1, wherein the initial resource bandwidth spans entire frequency domain bandwidth of the associated bandwidth part. 
     Aspect 3: The method of any of aspects 1 through 2, wherein the two or more bandwidth parts are configured for full-duplex communications between the UE and the base station, and the initial resource bandwidth spans a portion of an associated bandwidth part of the two or more bandwidth parts that is compatible with half-duplex communications. 
     Aspect 4: The method of any of aspects 1 through 3, wherein the receiving comprises: receiving RRC signaling that configures the two or more bandwidth parts, the two or more resource bandwidths, and one or more initial resource bandwidths within one or more of the bandwidth parts. 
     Aspect 5: The method of any of aspects 1 through 4, wherein the initial resource bandwidth is configured within one or more uplink bandwidth parts of the two or more bandwidth parts. 
     Aspect 6: The method of aspect 5, wherein the initial resource bandwidth has a bandwidth identification within a corresponding uplink bandwidth part of the one or more uplink bandwidth parts, and a corresponding downlink resource bandwidth has a corresponding downlink resource bandwidth identification within a downlink bandwidth part. 
     Aspect 7: The method of any of aspects 1 through 6, wherein the initial resource bandwidth spans contiguous or disjoint frequency domain resources of the associated bandwidth part. 
     Aspect 8: The method of any of aspects 1 through 7, wherein a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths, none of which are configured as the initial resource bandwidth. 
     Aspect 9: The method of any of aspects 1 through 8, wherein a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths that are configured with one or more random access occasions. 
     Aspect 10: The method of any of aspects 1 through 9, wherein the determining comprises: determining, by a medium access control (MAC) entity at the UE, to transmit the random access request for communications with the base station. 
     Aspect 11: The method of any of aspects 1 through 10, further comprising: determining to transmit the random access request using the active resource bandwidth when the active resource bandwidth has one or more random access occasions. 
     Aspect 12: The method of any of aspects 1 through 11, wherein the selecting further comprises: switching the active resource bandwidth from a first uplink resource bandwidth to the initial resource bandwidth based at least in part on the first uplink resource bandwidth having an absence of random access occasions. 
     Aspect 13: The method of aspect 12, wherein the selecting further comprises: switching a downlink resource bandwidth to correspond with the initial resource bandwidth. 
     Aspect 14: The method of any of aspects 1 through 13, wherein the selecting further comprises: determining that the active resource bandwidth within an active uplink bandwidth part is not configured with a random access occasion, and that an initial resource bandwidth of the active uplink bandwidth part is not configured or is configured without a random access occasion; and switching the active uplink bandwidth part to an initial uplink bandwidth part that is configured with the initial resource bandwidth that includes the first random access occasion. 
     Aspect 15: The method of aspect 14, wherein an active downlink bandwidth part corresponds to the initial uplink bandwidth part, and an active downlink resource bandwidth corresponds to the initial resource bandwidth, subsequent to the switching. 
     Aspect 16: A method for wireless communication at a base station, comprising: transmitting, to a UE, configuration information that indicates two or more bandwidth parts of a channel bandwidth and two or more resource bandwidths within one or more of the bandwidth parts, the two or more resource bandwidths including an initial resource bandwidth having one or more random access occasions; configuring the UE with an active resource bandwidth for communications with the base station that has an absence of random access occasions; and monitoring the one or more random access occasions of the initial resource bandwidth for a random access request from the UE. 
     Aspect 17: The method of aspect 16, wherein the initial resource bandwidth spans entire frequency domain bandwidth of the associated bandwidth part. 
     Aspect 18: The method of any of aspects 16 through 17, wherein the two or more bandwidth parts are configured for full-duplex communications between the UE and the base station, and the initial resource bandwidth spans a portion of an associated bandwidth part of the two or more bandwidth parts that is compatible with half-duplex communications. 
     Aspect 19: The method of any of aspects 16 through 18, wherein the transmitting comprises: transmitting RRC signaling that configures the two or more bandwidth parts, the two or more resource bandwidths, and one or more initial resource bandwidths within one or more of the bandwidth parts. 
     Aspect 20: The method of any of aspects 16 through 19, wherein the initial resource bandwidth is configured within one or more uplink bandwidth parts of the two or more bandwidth parts. 
     Aspect 21: The method of aspect 20, wherein the initial resource bandwidth has a bandwidth identification within a corresponding uplink bandwidth part of the one or more uplink bandwidth parts, and a corresponding downlink resource bandwidth has a corresponding downlink resource bandwidth identification within a downlink bandwidth part. 
     Aspect 22: The method of any of aspects 16 through 21, wherein the initial resource bandwidth spans contiguous or disjoint frequency domain resources of the associated bandwidth part. 
     Aspect 23: The method of any of aspects 16 through 22, wherein a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths, none of which are configured as the initial resource bandwidth. 
     Aspect 24: The method of any of aspects 16 through 23, wherein a first uplink bandwidth part of the two or more bandwidth parts is configured with two or more resource bandwidths that are configured with one or more random access occasions. 
     Aspect 25: The method of any of aspects 16 through 24, wherein the random access request is transmitting by the UE using the active resource bandwidth when the active resource bandwidth has one or more random access occasions. 
     Aspect 26: The method of any of aspects 16 through 25, wherein the UE switches the active resource bandwidth from a first uplink resource bandwidth to the initial resource bandwidth based at least in part on the first uplink resource bandwidth having an absence of random access occasions. 
     Aspect 27: The method of aspect 26, wherein a downlink resource bandwidth for a random access response transmission corresponds with the initial resource bandwidth. 
     Aspect 28: The method of any of aspects 16 through 27, wherein the initial resource bandwidth is in an initial bandwidth part that is configured with random access occasions, and the active resource bandwidth of the UE is not configured with a random access occasion, and an active uplink bandwidth part of the UE is not configured with an initial resource bandwidth with a random access occasion. 
     Aspect 29: The method of aspect 28, wherein an active downlink bandwidth part corresponds to the initial uplink bandwidth part, and an active downlink resource bandwidth corresponds to the initial resource bandwidth, subsequent to the switching. 
     Aspect 30: An apparatus for wireless communication at a UE, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 1 through 15. 
     Aspect 31: An apparatus for wireless communication at a UE, comprising at least one means for performing a method of any of aspects 1 through 15. 
     Aspect 32: A non-transitory computer-readable medium storing code for wireless communication at a UE, the code comprising instructions executable by a processor to perform a method of any of aspects 1 through 15. 
     Aspect 33: An apparatus for wireless communication at a base station, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 16 through 29. 
     Aspect 34: An apparatus for wireless communication at a base station, comprising at least one means for performing a method of any of aspects 16 through 29. 
     Aspect 35: A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to perform a method of any of aspects 16 through 29. 
     Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein. 
     Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. 
     The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration). 
     The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. 
     Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random-access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media. 
     As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.” 
     In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label. 
     The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples. 
     The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.